No, Taker will face Lesnar to get his long wanted win back (since Lesnar left when he was supposed to job back in 04) and Rock vs Cena II will happen with the title on the line. I don't really know what Punk can be doing, I hope he'll just be left in the cold deep in the undercard.
Punk will probably fight Ryback for the title. I'm not sure Rock will win the title at RR after all.
As for Taker/Lesnar, while it absolutely should be a lock for WM, it doesn't seem like it is. Lesnar/HHH unfortunately seems like the lock for the event. Shame because the match was really nothing special the first time around, and I can't see WM being any different. I suppose Taker/Lesnar isn't completely off the cards yet, but those heavy hints in the HHH promo about him probably not being done and how he wants to come back and overcome Lesnar, but not sure if he can just smells badly like seeds to the rematch where HHH overcomes Lesnar and becomes 'The Game' again... even though he won't be back full-time anyway.
As for the possibility of Taker/Punk at WM, the only chance I can see that happening is if Lesnar/HHH is a lock, they don't want to do Taker/Ryback yet, and Punk can't get into the Rock/Cena match and make it a triple threat for the title after losing it to The Rock. But the story for Taker/Punk plays itself out. Punk after losing the WWE Title and being unable to secure a rematch looks for another way to make a big splash and gain the respect of the WWE universe. He announces that he will force the fans to respect him when he goes to Wrestlemania... and defeats The Undertaker.
The next step is very important because Punk is no threat to The Undertaker under normal circumstances. They need to play into the story how Undertaker's last four WM bouts have caused him to get weaker and weaker and weaker and the fact he's taken two year-long breaks proves it. Punk needs to play up that fact because it's the only way there could even be a smudge of belief that Punk could beat Taker (and I know to a lot of people even with that, Punk still wouldn't be a believable threat to the streak). Maybe have Punk get the upper hand on Taker in a segment. Have them trade blows and Taker seems to be getting the upperhand. Taker then goes for the tombstone but Punk gets out of it and hits the GTS, proving dominance and that what he says is true and that Taker's streak is in grave danger. Build up on that for weeks similar to how they built Taker/Kane for NOC 2010, and combine that with the whole Punk respect angle, and it could be an excellent feud and an amazing match. The match would follow the formula of the Taker/Punk match from SD 2010 which was arguably TV MOTY, only would be longer and more dramatic. I think it could work. Taker/Punk is never going to be bigger than a Rock match or a match with two stars the caliber of Lesnar and HHH, but it will feel like a match that's a true main event level match for Mania and could be the main event if not for Rock and Lesnar/HHH.
But of course, that's only if for some idiotic reason they don't go with Taker/Lesnar. If they do that and go with Rock/Cena II for the title, I could see Punk either going after the WHC, or preferably, facing HHH, who he'd goat into facing him after HHH has had his confidence shaken by Lesnar. Punk preys on that and it creates a dynamic HHH has to overcome... only he doesn't, and Punk solidifies HHH's retirement by defeating him at WM.
One other idea, that in no way should happen with all the other options available, and probably won't happen because not even WWE is this stupid, but still could be interesting if done right is if they had Taker and HHH team up to face the two "Heyman Guys", Lesnar and Punk. HHH after spending two years trying to end the streak now has come to defend it. Shouldn't happen, but just something fresh to throw out there since we've been talking a lot about the predictable Taker/Lesnar and Punk/HHH or Taker/Punk and Lesnar/HHH combinations.