Like it or not, the brand extension is here to stay and will continue with each brand having their own champion. The format will eventually change, and already has with the removal of single brand ppv's. I personally don't like it, and never did, but I think WWE fans are stuck with it until WWE legitimately starts losing money by the truckload on any particular brand, and their network cancels them. As things look, this is a ways off, and as long as Vince is making money on any of them, he isn't going to change that formula, regardless of logic or a watered down product.
There is an over saturation of talent, as well as older talent and main eventers not retiring or working elsewhere as there are only so many spots and money to go around in TNA. This began when ECW and WCW closed their doors, and all of the sudden there were 100+ high quality wrestlers w/nowhere to work. This in turn has lead to an unbalanced card, and underdeveloped under card wrestlers. While in years past, ample time could be devoted to a tag team division, midcard/IC title, and low card guys to develop into stars of the future and learn how to draw, those same spots are now taken up by an abundance of main event talent with nowhere else to go.
At this point, each brand having its own champ is a necessity that WWE cannot live without. There is too much talent out there for 2 or even 4 hours of tv wrestling per week, and it is nothing new for promoters to invent or in these cases revive titles to make the product seem more exciting and important. A prime example of this is the invention of the IC title in the late 70's, b/c up until then there were only so many spots to go around for WWWF championship contenders.
Make no mistake though; while there may not be a single top title, there will always be a single top champion and that is whoever is headlining Raw. Better in quality from time to time or not, Smackdown is and always will be the "B" show, and top stock will always be put into the Raw champ and top Raw contenders. Raw is the flagship, and whoever rules the Raw world, regardless of whether he is the WWE, World Heavyweight, or ECW Champion, is the top champion in WWE's eyes. If you need any proof of this, ask yourself when the last time was that HHH wrestled for the top title on Smackdown, and how long did he stay on the brand?
now days, alot of guys are getting titles that don't deserve it. bobby lashley, sure he was great at the time, but when i look back, does he measure up to the likes of austin, rock, hhh, hogan, hbk, and even cena? not in my opinion. john cena, like it or not, is the hottest thing in wwe; has been for the past few years. make him the sole champion could only take him to that next level like it did for guys like austin and rock.
Firstly, becoming sole champion did not take Austin or Rock to the next level. When Austin became champ, he was already the hottest thing wrestling had ever seen, and Rock was well on his way to joining him when he beat Mankind at Survivor Series '98. If giving them the title did anything, it said to the fans that WWF trusted that these were the men who should carry the mantle and be the face of the company itself. This is exactly what they are doing with Cena, and to a slightly lesser extent Orton and Edge. Secondly, it is unfair to compare any of the top guys(Orton, Edge, Batista, Cena) to the group listed above, if only b/c of when they wrestled. For anyone that was there and lived through the boom "Attitude Era", consider yourselves very lucky. Whether you are a fan of the style of booking used in that era or not, the quality of the talent in that era is something we might never see again. Austin, Rock, Foley, Taker, HBK, HHH, are some of the best EVER. Their merits hold up against any other generation of professional wrestlers and that is a testament to all of them as well as the exposure they received when they were in their prime.
This is not to take anything away from the stars of today, but time will tell, and if we are talking about Edge, Orton, Batista, and Cena in 10 years the way we talk about said Attitude era stars today, then that comparison will be a fair one. The fact is that the guys that are on top today are there, and whether we all want to be nostalgic about yesteryear or not, they are the best out there right now and nothing shy of Vince McMahon's mighty right hand is going to change that.