The George St Pierre workout is designed to build a body that is strong and nimble enough to really lay a beating on someone. George is one of the best MMA fighters in the entire world, (I like to think he is simply the best pound for pound, but I am biased because we are both Canadian's).
It would be difficult to explain the George St Pierre workout in words, because he likes to do things a bit different. He is very into working out a bit different then the standard muscle building workouts.
Before you check out the video, remember that GSP also spend a large amount of his day practicing where he is wrestling and doing boxing and kickboxing. You could replace this with some high intensity interval training and achieve close to the same results.