Actually Savage vs Steamboat didn't get a 5 star rating so that match wouldn't count. The following matches in the WWE received a 5 star rating from Dave Meltzer. (Not including CM Punk vs John Cena) 1.
3/20/94 Shawn Michaels vs. Razor Ramon (Ladder Match, WrestleMania X) (Received MOTY) 2. 8/29/94 Bret Hart vs. Owen Hart (Cage Match, SummerSlam 1994) (Didn't Receive MOTY) 3. 3/23/97 Bret Hart vs. Steve Austin (I Quit Match, WrestleMania 13) (Received MOTY) 4.
10/5/97 Shawn Michaels vs. Undertaker (Hell in a Cell Match, In Your House: Badd Blood) (Didn't Receive MOTY) So in actuality there is a 50/50 chance that Punk vs Cena will receive Match of the Year honors. WWE will usually go for the match that was on a bigger stage like WrestleMania, so I wouldn't be surprised if they chose Taker vs HHH over Punk vs Cena.
I have a feeling it will win Match of the Year mainly because of the history that when you get a 5 star rating it wins the Match of the Year.. unless another match can do better than Cena vs Punk (which will be pretty tough to do) then I see Cena vs Punk easily winning MOTY just because of the storyline and the match quality itself.