BJ is going to have to pull off a minor miracle on the ground since he is outmatched by GSP in every other facet of the game (size, striking, takedowns, takedown defense, mental, conditioning). Luckily, BJ has 5 rounds and the fact that the only time he was finished in his career was due to a cracked rib. Its a tough one to call, but I think the good money is on GSP.
Oh, and Shogun over Coleman was an easy one to call. Did you guys see their first fight in Pride? Shogun was winning and had to stop due to a fluke injury when he tripped.