Let's look at these one by one.
Tim Sylvia: He is currently demanding the highest downside guarantee of any fighter in The UFC. He's not going to get it, and he'd be a hilarious trojan horse to send to M-1. He's not a draw at all and he might manage to decision Fedor.
Andrei Arlovski: First, I think he will re-sign after this fight. UFC needs marketable heavyweights now more than they did before, and when he sees how dry the landscape is beyond Zuffa, he'll sign. If he does sign elsewhere, the impact is bigger than Sylvia, but still minimal.
Tito Ortiz: This is the only name that could do something for another promotion at this point. He's arguably the biggest draw in UFC history, and if he beats Machida he can reasonably call himself a top LHW. As much as a fight with Frank might draw, the real draw for Gary Shaw and co. would be a Kimbo/Tito fight. There is only one thing standing in the way of all this happening: Zuffa has a right of first refusal on Tito's contract. Whatever his top offer is from competition, they have a right to match it, and they just might do it if they feel there is a big threat. More legal trouble ahead? Bleh.