OK, let's see:
A WWE normally takes 2 hours 30 minutes.
The Rumble will get, at the very least, 57 minutes (38 entrants x 1,5 minutes each entrance) + two "long" entrances at the beginning (5 minutes at most) + 7 extra minutes of the final guys in the rumble and celebration.
Then we still have 1 hour and 10 minutes.
The divas match should get 10 minutes the entrances + 5 minutes post-match beatdown by "youknowwhoisbigandblackandisdebutingattheRumble".
That gives you 55 minutes for 2 matches, which is WAY too much time (specially considering Orton vs Miz is gonna be shit). I'd add a US title match or a Tag Team title match...