I'd like to see more of the secondary characters appear in the new movies. Especially Christine Chapel, I've always been very fond of her. I think that Chapel should've been Spock's love interest, and Uhura with Kirk. We did get a mention of her in the new movie, even if it was pretty awful to learn that she left the Enterprise after a one night stand with Kirk and he didn't even remember! I know Kirk is promiscuous, but it seems pretty unprofessional that he's so casually sleeping with his crew members.
I'd like for Chapel to appear in a new movie, and maybe she could have a romance with McCoy this time around since Spock is spoken for.
I think Charlize Therzon would be a good casting, she has a similar cool stautesque beauty to Majel.