Diaz isn't going back to the UFC, he is too small to match up against the top guys at 170 and 155 would be a very hard cut for him, 160 is hard enough. If EliteXC folds Diaz will continue to fight in DREAM and the occasional Affliction or other upstart promotions shows.
I think Shields, Lawler, Noons, Le and Villasenor would all be locks to get scooped up by Dana quickly.
Kimbo would want too much money and in turn would headline smaller promotions for big purses.
Ninja and Bigfoot could go anywhere, The UFC would be stupid if they didn't pursue Bigfoot, because he is a top HW and the UFC is very thin at that division. Ninja would also add some depth to the 185 div.