I don't think they are gonna out Riggs like they did to Loiseau if he loses (in light of what's happened to him lately.)
Riggs is still young too. He's fought at 300+ so he can go to any weight class he chooses. I think he's going to beat Sanchez myself. Here's what I see happening:
Riggs wins - (Riggs fights Hughes unless Hughes vs. GSP is already set up) otherwise, Riggs fights BJ Penn, or possibly Matt Serra after he loses.
Riggs loses - if he stays in the UFC, he'll get someone like Chris Lytle. Or he moves up to 185.
Sanchez wins - fights BJ Penn while Hughes vs. GSP 3 is going on. IF he beats BJ (and I highly doubt this as BJ will be fully trained for that fight) then he gets his title shot.
Sanchez loses - he falls off the face of the Earth for a year or two until he comes back with an even dumber ring entrance.