Even though a fight with Vitor would be entertaining, he hasn't proven to be a top Middleweight yet. Sure he did awesome at 195, but what about 185? He should fight a guy like Chris Leben, and if he can win decisively, then he should get a shot.
Okami should be next, just because nobody else is left and there is some marketing to be made based on the previous and controversial match b/w Okami and Silva.
Sonnen should fight Bisping on the same card as Anderson and if he wins, he should get a title shot against the winner. If Bisping wins, he should probably fight the winner of Marquart/Palhares for next in line.