It's more the HBK fan in me wanting him to get one last run with the title that makes me say that.

Triple H could probably give Miz that bump, but it could be beneficial for say... John Morrison. Just a thought, but I doubt it'll happen. Shawn seems very content to be retired and working on other projects right now, and being around his kids as they grow up. At least that's the impression I get from following him on twitter/Facebook. But I could see him doing the short-time run with Hunter for sure, and it would keep Hunter out of the title picture for a while longer for Cena/Miz to finish up.
I don't know if I'd call Orton so much a face as he is a tweener. He seems to work well in that role, as do Edge and even Triple H when they're booked that way.
If I was booking the product right now, I would put Cena over Miz at Mania on Sunday. I'd keep Triple H out of the title picture for a while longer, via the program with Shawn we've created. I'd then start a Cena heel turn (which I know Vince won't ever do), probably through him continuing to bad mouth and eventually attack the Rock like he did on Monday. Hell, for all we know that could have been the purpose of that. At that point, I think I'd keep Sheamus and Danielson, err... Daniel Bryan going at it for the U.S.Title. Then elevate John Morrison into a program with the Miz, and perhaps Ziggler briefly. Have the Miz get his rematch for the WWE Title, and build into a three-way fued for the WWE title... with Cena in the midst of a heel turn, Morrison as the face, and Miz as the heel.
I'm pretty certain this will never happen though. Morrison is going to be relegated to his program with Ziggler right now, and will continue being mid-tier, maybe getting a program for the U.S. title again. Cena will remain Super Cena, decimate the Miz at Mania, and then beat the crap out of the Rock for good measure. Then Triple H will come back in and begin a year long program with Cena, thus ensuring he gets a chance to give 20 minute monologues at the beginning of every RAW. He'll then eventually become the 14-time World champion, and run roughshod over the entire roster before eventually retiring.

At least that's how I figure Vince will book it based on his history. :24: