Is Georges St. Pierre having doubts about a potential fight against Anderson Silva?

It sounds like that may be the case in a recent interview after UFC on Versus 3 (transcription via Bloody Elbow):

"I don't know (about fighting Anderson Silva). I need to sit down with my entourage and see first where this fight will take place and what weight, and a bunch of stuff. Right now I'm focusing just on Jake Shields, I don't see further than Jake Shields. It would take a long time (to add the size). Anderson Silva is a huge guy; he's weighing around 230 pounds. He's very big. Even when he fights as a light heavyweight, he looks bigger than the other guys. I don't know if I'm going to go up (to) 185. I have no idea; it's a complete reorientation of my career. I have a lot to lose and I haven't thought about it, I haven't sat down to talk about it."

Interesting words coming from Welterweight Champion Georges St. Pierre as the highly anticipated superfight against Anderson Silva gets closer and closer to becoming a reality. If "Rush" gets past Jake Shields at UFC 129 on April 30, Dana White has made it clear the next step in the French-Canadian's quest to become the greatest of all time will be to defeat the promotion's middleweight kingpin. But from the sounds of it, "GSP" is having second thoughts of jumping up to 185-pounds. After all, "The Spider" is has enjoyed a size advantage against damn near everyone he has fought. In fact, even when he went toe-to-toe against Forrest Griffin, a gigantic light heavyweight, he sized up rather well and it didn't seem to have any effect on his game. Is that weighing heavily on St. Pierre's mind as the fight gets closer to actually happening? Or is he just focused too much on defeating Shields and tiring of questions about a move up in weight class?