Spock was my favorite, which means no change from TOS. The events of the movie will send Spock's character in a different direction from Spock Prime.
McCoy - well cast, I'm interested to see more from that character.
Kirk and Uhura both underwent some pronounced changes from TOS. In Kirk's case, probably to give him a distinct character arc (differentiated from Spock's - TOS implied that young Kirk was serious and grim) and Uhura of course because her passive, lady-like qualities in TOS wouldn't play well today. I'm ok with both changes, since they were necessary.
My hunch is that both Kirk and Spock will have opposite character arcs. Kirk will grow up, become less wild, and start to show more of the leadership qualities, compassion, and strategic savvy that we're familiar with. Spock will struggle more to control his vengeful, dark side than Spock Prime ever did, and his relationship with Uhura will also create a challenge for emotional restraint.
So, we're going to see Kirk grow into the character we're familiar with, and Spock grow away from the familiar character. If that's the plan, I like it: the characters on opposite trajectories. I don't think the other characters need arcs, because there's only so much you can do with three 2-hr movies. Both Uhura and McCoy will probably continue to be the important secondary characters.
