Oooooo.... Zach Quinto. Good choice.
I thought Matt Damon was a good choice for Spock. But at the same time, I think casting a really BIG name actor is probably a bad idea. If the franchise reboot is a success, you want all the main characters to be prepared to stick around.
So someone like Quinto is an excellent choice - he has a moderate profile due to his work on heroes, but he's hardly a mega star. And Gary Sinese as Bones is... visually speaking at least... perfect, just perfect.