The Shield is going to get involved for sure. They call themselves a shield against injustice, well I could picture Rock getting attacked by the Shield because he didn't earn his title shot, it was given to him
Interesting little Dynamic there with Reigns too. It probably won't be mentioned but in passing, but that Maivia/Anoa'i family tree could be played out pretty interestingly.
I do see The Rock as the first person to fight them off though, on his own.
I could see this happening as The Rock has put people over before, however this is 2012 Megastar-not-just-in-wrestling Rock. I would think WWE wouldn't let him lose.
I would not like to see The Rock return for the night and win the title though, but I can see a Cena/Rock/Punk Triple Threat at Mania.