I dont really know why people say Punk isnt needed on Raw cause yes he is. There aint much contenders left to face Orton or even Cena for the title. Sheamus has faced both, Barrett's facing Orton now and in a feud with Cena at the same time. Edge is on SD, Jericho's gone, JoMo, R-Truth, Daniel Bryan wont certainly be pushed anytime soon, just Miz is left as he has MiTB. And god forbid Barrett wins the title off Orton. Barrett isnt ready for the title yet, he's still a rookie, so it would be stupid if WWE put it on him even he's over in this feud with Cena. And for Cena, after he's done with Barrett, he pretty much will have feuded with every main eventer on Raw except for Miz (not counting Miz's feud with him when Miz was a mid carder). So yeah, Raw needs Punk right now for Cena & Orton to feud with in future.
Plus Punk wasnt on SD this week and the obvious is he has nothing left on SD, so it must mean he's going to Raw. Edge & him are like one of the same really, so it's an even trade.