He does seem a little aprehensive when it comes to this superfight. To be honest, I just don't think he wants to focus on anything else right now other than the Condit fight. When he wins and Anderson enters the cage to challenge him, I'm sure with all his adrenaline going, GSP will accept the fight.
I don't think Silva would enter the cage and challenge him. He doesn't seem to be this type of guy. At least not directly.