I think a fight with Shields could be interesting. Weidman wants a title shot so doubt he would take the fight. Would Tim's foot heal in time? A completely off the wall idea have him go to Strike Force and fight Rockhold for that title.
Now that is an exciting match-up. In my ideal world, they would do it Cormier/Mir style and have it one night only. But honestly, Rockhold and all the other MW's will end up in the UFC once that division dissolves.