Even though I don't think they can wait that long to pull the trigger on Alberto Del Rio, I think it makes much more sense for him to be the Money in the Bank winner. If they keep the Wrestlemania MITB match I would pretty much guarantee Del Rio to win it, of course that means he loses tonight.
I don't see both current champions leaving Elimination Chamber with their belts. So here is my fantasy booking/predictions:
Miz keeps his belt through Elimination Chamber.
Cena wins the Rumble and Challenges Miz at 'Mania.
They push the Corre/Nexus feud tonight and they face off at 'Mania.
Sheamus finds his way in to the Smackdown Elimination Chamber match and wins.
HHH Returns to challenge Sheamus at 'Mania
Dolph/Vickie cheat Edge on his loss at Elimination Chamber with the help of someone else (Jericho?)
Edge/Orton (or Christian) vs Dolph/Jericho? at 'Mania.
Jerry Lawler vs Michael Cole at 'Mania. Possibly a tag match.
Kong/Lay-Cool/Melina/Alicia Fox vs Beth/Natalya/Kelly Kelly/Eve/Gail Kim at 'Mania
Del Rio, Kofi Kingston, Evan Bourne, Daniel Bryan, John Morrison, Ted DiBiase, Cody Rhodes, R-Truth, Tyson Kidd in Money in the Bank at 'Mania.
Tag Team turmoil match at 'Mania (Pre-Show) with whoever's left. (Santino/Kozlov, Usos, Hart Smith+Tatsu, Ryder+Regal, Primo+Chavo, Henry+Tarver)
I could see them "wanting" to run with Undertaker vs Kevin Nash now but that match has disaster written all over it and I think/hope they know that.