This is a very, very interesting match. There a lot of ways for it to go down. It all depends on why exactly the WWE is bringing the Rock out now. There's still a good ways to go down the stretch to WrestleMania. If they really intend on building the Rock vs Cena nonstop till then - which I think is an awesome move, by the way - then this goes does down a different way than if this is just trotting out the Rock to remind us about him and then bringing him back sometime after the Rumble. Keep in mind I have no idea what the Rock's filming schedule is like, so I don't know how feasible it is that he would be here from Survivor Series to WrestleMania in a straight shot.
The other thing that has to be considered is this - the WWE is staring straight down the barrel of another Hogan vs Rock, wherein the crowd at WrestleMania 28 will turn on Cena so hard - and not just there, but worldwide - that he might be unable to recover as a face. The thing is - Vince isn't an idiot. He knows there is potential for that. And I think he might want it. As cliche as it is, as tired as it is to keep saying that Cena's going to turn heel, so on, so forth, I really think it might happen at WM 28 this year. The reason I mention this here is that I think it means there is no way that Cena turns here, as some have been suggesting. It doesn't mean that Cena won't attack the Rock, however - there's a difference.
If the WWE intend to just trot the Rock out, what I think might happen is this. They tease the lack of cooperation for the whole build, they try to show each other up throughout the match, and somehow they win because they're Supermen. Then, afterwards, Cena lays an AA on the Rock to close the show. I don't think this turns him heel, anymore than the Rock Bottom at WM 27 turned Rock heel. I think that the Rock will bitch about it on Twitter but leave it well enough alone until they go down the road to WrestleMania.
But, if they intend to start the long term build right now...then I think the right move is for them to lose. Their lack of cooperation would cost them the match, though through no lack of Miz and Truth shenanigans. I don't think either should walk out, but perhaps Johnny Ace could involve himself in some tricky way. I'm not too sure, obviously they won't look too weak in the loss. Have them piss off the Rock somewhere down the way so he has incentive to stick around. Rock and Cena might then decide to stick together and take revenge at TLC.
It's a complex puzzle and there are a lot of variables that go into how this match plays out, which I think makes it incredibly exciting. Played correctly, the tension between Rock and Cena will be thick enough to cut with a knife and the question of who turns on who - and when - will be very hot. I hope that they do a straight build from here to Mania, and I'm excited to see how it starts. My gut is saying that whether or not they're doing the straight build, Cena and Rock will win. As much as I think it'd make sense to stretch the Truth/Miz feud a bit, I'm having trouble honestly believing that the tag team of Cena and Rock will lose.