I really don't see the fight happening. I think Silva wants it, but seems like GSP is unwilling, as he said he would have to take a whole year off to build up muscle mass to make 185. Only way it goes down is at a catch weight 180. Both guys are one or two fight from having no one to face so it makes sense for it to happen and then GSP can stay at WW and Silva can either hang it up, or move up to 205.