Pretty good breakdown from Nick, he was pretty accurate on GSP's gameplan for the Condit fight. Georges pressured with his boxing, specifically his jab, and then shot for a takedown and used his top control to keep Condit out of his area of expertise. I think everyone forgot how active Carlos is off of his back and how much he could do from the ground but none of that paid off against GSP when he moved into half-guard and dominated the grappling exchanges.
Nick will have a problem with St.Pierre's wrestling, period. He'll go for a ride or to, getting slammed around is something that happens to the Diaz boys a lot in their fights against wrestlers. Diaz will probably try to counter with a Kimura like he always does but he'll be put into the fence and basically held there for the last minute or so of each round in a potential GSP fight. GSP is also much too fast on his feet and has an amazing ability to control the distance in the standup.
I really don't see a way Diaz can beat GSP unless Georges makes a huge mistake and gets submitted. He's too fast to be pushed up against the fence and too strong (and too defensively solid) to get put in a bad position on the ground.