I would say that Cena probably deserves to break the record, even putting aside that the title has been devalued in today's wrestling industry.
Think about the wrestling landscape since Wrestlemania 1 and how long the top guys have held on for.
Ric Flair arguably became the number one NWA (without any doubt about him being it long term) in 1985. By the time he left for WWF in 1991 the NWA was pretty much gone, WCW was a joke and he (arguably again) wasn't the top guy in the company. At the very least the company wasn't built around him any more. When he came back business was lukewarm and Hogan wasn't long behind him. Total time as top guy = 6 years
Hulk Hogan was the number one WWF guy from Wrestlemania 1 - 6, no questions asked (although Macho Man might have if he'd been positioned as a babyface champion). From then until Wrestlemania 9 he was kinda the top draw, he obviously wasn't around much between WM 8 & 9, Warrior was on top for much of the time after Wrestlemania 6, but overall you'd still say he was their number one guy.
He went to WCW, did lukewarm business until the nWo hit in 1996, with that run ending in 1999 when he and the company started throwing anything at the wall to make something stick. Total time as top guy = 9 - 12 years
Bret Hart picked up Hogan's ball in 1993 and ran with it til passing it off to HBK in 1996, arguably you could say he was the WWF's MVP in 1997 as well. Total time as top guys 3 - 4 years
HBK, never really got going as a face champion but was positioned that as the main guy in the company, arguably he was the MVP of 1997 in WWF. Total time as top guy 1-2 years
Steve Austin, arguably the biggest star in the wrestling from 1998 - 2001. Total time as top guy 3 years.
The Rock, arguably the biggest star in the wrestling world from 1999 - 2002. Total time as top guy 3 years.
Triple H & Brock Lesner - Take your pick as to who was the WWE's number one guy until Cena took over in 2005 Total time as top guy 3 years max depending on who you pick
John Cena - 2005 was his big 'I'm the man' year. He's had a strangle hold on being the top wrestling star in the world since then. Total time as top guy 7 years and counting.
So already only Hogan has been the top guy in the world for longer than Cena, and with Cena at least 7 of those years are inarguable. Some of Hogan's (1992, 1993, 1999) are very shaky and probably shouldn't be counted.
Flair was NWA Champ for two and half years straight 1981-83 and 1984-86, Im not sure how you can say he didnt become a "Top Guy" until 1985, that's like saying The New England Patriots didnt become champions till 2004, neglecting the two Super Bowls they won in 2001 & 2003.
As for Cena, if he does break the record long time fans will not pay as much attention to it because his reigns have been shorter. Now that is in part due to the change in the business model, top quality matches on live TV every week and monthly PPV events means faster storyline progression. Up until Eric Bischoff and the advent of expanded PPV and Monday Nitro the pro wrestling business model was slower storylines, played out all over the house show circuit, culminating at one of the handfull of signature events each year (WrestleMania, Starrcade, Great American Bash, SummerSlam, SuperBrawl, Royal Rumble). Cena's reigns have been shorter, not necessarily because he isnt popular but because storylines move faster.
In 1987 Flair had only four feuds - the end of the 1986 Nikita Kolloff fued through Feb, Barry Whyndam March-May, Jimmy Garvin May-July, and Ronnie Garvin Aug-Nov. He was champ almost all year except a 2 month period rihgt before Starrcade 87 in late November, main evented all over the US, yet had only four steady feuds, one of which was ending as the year began, having started in Oct of 86.
Randy Savage's last WWE Title run lasted 6 months (April-Sept 1992) and he had only two feuds, Flair & Ultimate Warrior. For a guy who is World Champion, wrestling constantly, that wouldnt happen today.
Now, if Flair didnt consistently draw well, especially since the house show business was more essential to company income without the PPV revenue that exists today, he wouldnt have had multiple reigns each lasting between 13 months and 26 months. Likewise the belt wouldnt have kept coming back to Cena after short hiatuses if he wasnt popular with the fans.
Still, to me because Flair had so many reigns of extreme length his record is more impressive than what Cena has right now. Flair held the World Tile for at least part of the year every year from 1981-1996, 15 consecutive years, absolutely amazing. During those years he defended the title against Hogan, Savage, Harley Race, Sting, Brett Hart, Undertaker, Dusty Rhodes, Ricky Steamboat, Lex Luger, Bruiser Brody, Terry Funk, wrestled Title vs Title matches vs WWE Champ Bob Backlund (1983) & AWA Champ Rick Martel (1985), wrestled numerous title matches in Japan & Puerto Rico as well as Germany and New Zealand among other places, it's an amazing run. The legendary names that Flair defeated for title wins including Hogan & Savage, Sting, Rhodes, Race reads like a veritable who's who of pro wrestling in the 80's & 90's. Cena simply hasnt matched that, and in some ways due to changes in the business he never will.
As far as the argument that some of his reigns were short, you can say that about almost any multi time champ, including HHH, Cena, Edge, Orton, and Hogan & Savage. The fact so many of them lasted 6 plus months overshadows that, especially considering how often he wrestled
(remember from 1981-85 Flair was averaging by his count around 380 matches per year counting his overseas bookings, tag team bouts, and TV tapings and even after 1986 up until the end of 1988 he was performing well over two hundred matches per year, similair to what today's full time wrestling stars do. )Jim Crockett Jr started restricting Flair's outside bookings in 86, not wanting him risking injury or making money for competitors as things became more heated with the NWA-WWE rivalry.
As far as "quality reigns" Flair's 1st (1981-83), 2nd (Nov 83-May 84), 3rd (May 84-July 86), 4th (Aug 86-Sept 87), 5th (Nov 87-Feb 89), 6th (May 89-June 90), 7th (Jan 91-July 91) and 11'th (Nov 93-July 94) all lasted roughly 6 months or more. He had two reigns separated by about three weeks between Dec 95-April 96 (basically to pump interest into a SuperBrawl Cage Match between him & Savage they had Savage beat him on a live Nitro a few weeks prior to the event, then Flair won it back on the PPV).
Just for reference, Flair's official Title Lineage reads like this...
1) NWA Title June 81 (def Dusty Rhodes) - Lost June 83 (Harley Race)
2) NWA Title Nov 83 (Race, at Starrcade) - Lost May 1984 (Kerry Von Erich)
3) NWA Title (Von Erich) May 1984 - Lost July 1986 (Rhodes)
4) NWA Title Aug 1986 (Rhodes) - Lost Sept 1987 (R. Garvin)
5) NWA Title Nov 1987 (R. Garvin, at Starracade) - Lost Feb 89 (Steamboat)
6) NWA Title May 1989 (Steamboat) - Lost June 1990 (Sting)
7) WCW Title Jan 1991 (Sting) - Lost July 1991 (Stripped)
8) WWF Title Jan 92 (Royal Rumble) - Lost April 1992 (R. Savage)
9) WWF Title Sept 92 (Savage) - Lost Oct 1992 (B. Hart)
10) NWA Title (also known as the "International Title" at one point) June 1993 (B. Whyndam) - Lost Sept 1993 (Rick Rude)
11) WCW Title Dec 1993 (Vader, at Starrcade) - Lost July 94 (H. Hogan)
12) WCW Title Dec 1995 (Savage, Starrcade - def Sting & Luger in Triangle Match immediately prior to title match with Savage) - Lost Jan 96 (Savage on Monday Nitro)
13) WCW Title Feb 96 (Savage, at SuperBrawl) - Lost April 96 (Giant, aka Big Show, on Monday Nitro)
14) WCW Title March 99 (H. Hogan) - Lost April 99 (DDP, in 4 Corners Match also involving Hogan & Sting)
15) WCW Title May 2000 (J. Jarrett, Monday Nitro) - Stripped of title due to injury by Vince Russo
16) WCW Title June 2000 (awarded title by Kevin Nash due to having never lost it in the ring) - Lost Title same night (J. Jarrett)
There is some discrepancy regarding two issues - one, some people do not like to separate the two reigns in May 2000 - WCW did officially recognize Jarrett & Kevin Nash as champs in between however so WWE and Pro Wrestling illustarted Magazine recognize them as two separate reigns.
Title reign #11 was "suspended" briefly in April 1994 following the "double pin" scenario in a PPV match vs Steamboast where it appeared both wrestlers pinned each other and WCW Commisioner Nick Bockwinkle ruled the bout a draw. Upset over the perception he should have lost, Flair "gave the belt" to Bockwinkle and told him to hold it till he beat Steamboat in the re match. Flair cleanly pinned Steamboat in the subsequent re match but WCW treated the affair as if the current reign had never stopped.
There is some dispute over a reign not recognized by many outlets, the infamous "Singapore Title Swap" where Flair & Race, headlining against each other on a tour of Asia, essentially swapped the title, Race wining the belt, setting up added interest in the subsequent re match in a nearby city with Flair, who promptly regained the title. Allegedly Flair & Race came up with this storyline on their own, it was not agreed to by Jim Crockett Jr or sanctioned by the NWA, in the US NWA Television and the Pro Wrestling Illustrated Magazines treated the affair as if it never happened.
In a Tokyo Dome match vs Tatsumi Fujinami in 1991 it appeared Tatsumi pinned Flair and won the WCW Title. However, WCW rules stated that an over the top rope dump could result in disqualification, and since Flair flipped Tatsumi over the top rope immediately prior to the pin being counted the match was over, Flair losing by DQ but retaining the title. The NWA Board of Governors, still in existence at this point and not officialy recognizing the WCW Championship as the same as the NWA title chose to recognize Tatsumi. The titles were again merged a few months later in the US when Flair pinned Tastumi in the re match. Wrestling fans at this time essentially considered the WCW Title as the newly re named but old, existing NWA Title, since the title was defended against all the wrestlers previously under contract to Jim Crockett Promotions under the NWA banner (now owned by Ted Turner & Turner Broadcasting, re christened WCW). Officially there was no interruption of Flair's World Title recognition.
Title reign 8 was the result of winning a 30 man battle royal, the WWF Title previously being stripped from Hulk Hogan and held up, to be awarded to the "Royal Rumble" winner, as a result of two highly controversial title matches (and title changes) between Hogan and Undertaker.
Title reign 14 was officially a "First Blood" match but the rules were amended before the bout started giving the referee discretion to stop match if one participat seemed unduly injured, not necessarily at the first sighting of blood. Consequently both Flair & Hogan bleed extensively in the match, held in a cage, until Hogan was "counted out" while stuck in the figure four.
In the early 80s, Flair would agree to "lose the title" in some of his indepenent bookings outside the US, setting up a bigger pay day for his anticiapted return and subsequent re match. Local wrestlers, popular with fans were typically the ones chosen to "win the belt". Flair typically would return a month or so after the "loss" and "regain" the championship. However, none of these were sanctioned by the NWA or agreed to by Jim Crockett Jr, as such in the US these "title switches" were never recognzized, Pro Wrestling Ilustrated Magazines and NWA affiliates alternately treated the matches as if they never happened, or were non title contests. Flair in interviews has estimated he maybe as many as 25 time champion counting these incidents.
in 1993 the NWA was promoting itself as a completely separate entity, a different company, but was partnered with the existing WCW, it's titles defended on WCW programs, it's wrestlers showcsed on WCW programs, and WCW wrestlers free to compete in the NWA. The situation was confusing to wrestling fans (think of WWE & Smokey Mountain Wrestling's association circa 1997, or the "roster split" of today). The NWA Title was recognized as a "World Title", making Flair's victory over Barry Whyndam at the 1993 Great American Bash officially title #10. Shortly therefater a falling out between NWA brass and WCW officials lead to the NWA no longe being affiliated with WCW. WCW had granted permission to the NWA to use the "Big Gold Belt" as it's championship belt, after the separation WCW kept the physical title belt, re named it the WCW International Title, and Flair promplty lost to Rick Rude. Eventually having two titles both treated like World Titles made no sense and International Champion Sting lost via pinfall to WCW Champ Flair in a Title Unification Bout in June 1994 (better known for Flair's heel turn, alliance with Sherri Martel, and Hulk Hogan's WCW debut). Flair was never granted an extra title here, basically his 11th title reign just "aborbed" the International Title.
. See, I can't even find the right words to express how I feel. Although Cena has a great chance to do it (given the facts that he's still in his prime and that he's only four World Titles away), it would be... 
