Having never played the SvR game(s), I hadn't seen that clip before (HHH saying the exact phrase "Champions of Champions" in the video game). That's a great comparison, and quite a curious turn of phrase for the WWE to be using again (especially coming from HHH in both instances). The Scooby Doo Wrestlemania DVD cover is another puzzling clue, thanks to Trail_Blazin for pointing that out (I found it on the first page of google results; it isn't hard to find if you want to see it). Even though he isn't front & center (Cena & Scooby are, of course), HHH is holding the belt in the background.
As it's already been said (practically ad nauseam at this point), Steph was always sure to include HHH's name on the list of former WWE and/or World Champions; acknowledged as "the best of all time" (however it was worded by Hunter on TV). HHH's inclusion on those lists could be a red herring, or could be Steph's way of foreshadowing HHH's win at TLC. HHH's latest sit-down interview with Cole was very similar, as even before I opened this thread and saw the video game comparison it seemed rather obvious that the point of the interview was to try and confuse the viewer(s) as to which Superstar The Authority is behind (or if HHH will insert himself in the match).
Personally, I'm leaning towards HHH coming out on top this Sunday as well. I know that some people have a problem with a "part-timer" being the World Champ, but The Rock recently held it as a part-timer. I know, I know...The Rock was champ leading into Wrestlemania, it was done to help the overall publicity of the event (and to further hype "Cena vs. Rock 2"), HHH is DEFINITELY not The Rock when it comes to the entertainment world, blah blah blah. I think that HHH might actually come back on a full-time schedule (albeit a short one) if he wins the title this Sunday. I think HHH might even be willing to work a few house shows (although not every single one). If HHH is going to become the first "Champion of Champions" (I won't even get into the main event of TLC being the "first" WWE unification match, because the idea is laughable at best), it seems to me that HHH would want put everything he had into the run. I could easily see him do a short full-time run (similar to RVD's run earlier this year, but with more house show appearances)...at least until HHH were to drop the strap, which would conceivably be at Wrestlemania 2014...quite similar to The Rock's last World Title run, around this time last year, don't you think? Hmmmm.....
The other thing that seems odd to me, is the amount of World Heavyweight Title reigns that Cena & HHH have amassed over their WWE careers. According to Wikipedia (so take that for what it is), Cena is cited as having held a total of 14 World Titles in the WWE (11 WWE Title reigns, and 3 WHC reigns). Wikipedia shows that HHH has had a total of 13 WWE World Titles (8 WWE Title reigns, and 5 WHC reigns). The statistics here are another factor (at least in my mind) that tip the scales in Hunter's favor this Sunday. From a storyline point of view, HHH wouldn't want Cena to get too far ahead of him in his number of title reigns, and that could be another reason that HHH decides that "The Game" is what's best for business. After all, who's better to hold the title "Champion of Champions" than "The King of Kings"? ...and not to beat a dead horse, but I could easily see HHH's ("real life") ego in need of some stroking after seeing The Rock hold the title 10/11 months ago. After all, HHH watched HBK fight The Undertaker twice at Wrestlemania, then he decided that he needed to do that too. The Rock's last title reign had to have sparked at least a little bit of that same competitive jealousy (for lack of a better term) in HHH. It wouldn't surprise most of the WWE Universe (or the IWC), at least.
Turning Cena heel doesn't seem smart at this point. Daniel Bryan turning heel (by HHH helping Bryan win the match somehow) makes even less sense to me, since The Authority has been harping on how Daniel Bryan is a B+ player (at best) ever since SummerSlam. To have Bryan suddenly be "good enough" to hold the "Champion of Champions" Title, the story-writing would have to be stretched so far that the plot would snap in half. However, if HHH does end up winning the title this Sunday, that could open up the possibility for Daniel Bryan getting to face HHH at Wrestlemania for the title. I know it's not the most likely scenario at this point, but it would make for the best possible ending for Bryan's title chase (and the demise of "The Authority"). Then HHH could have his "Rock Wrestlemania Moment", and appease his ego. In HHH's own little brain, he could say to himself "I put over a new Superstar, not "the face" of the WWE - like Rock did". It's just too easy to see it happening for me...then again, I don't have a crystal ball. If I did, I doubt I'd be using it to look at wrestling outcomes, anyway! Haha!
If Cena wins the title cleanly on Sunday, who cares? If Orton wins the title cleanly on Sunday, who cares? There has to be some sort of screwy finish, and I don't see Cena coming out as a heel here. That would mean that Orton would be sympathized with by the audience, ending his latest run as a heel. That wouldn't be unheard of, but it just seems too soon to change Orton back to a face. Especially since a double-turn would have to happen (even if Cena's heel turn is a two or three month "slow" turn).