Oh, I love the Game of Thrones. Definitely up there with LotR. I read all of the books last year and I wish there was a memory wiper available so that I could wipe my mind of GoT and read it all over again.
I'll have to watch the show before I make any judgments about if the actors fit, but the one they picked for Tyrion was in fact the person I thought would make a great Tyrion. I guess they thought so too.