Thats the biggest problem I had with the film, while everyone had expanded roles and lines, that was the problem - EVERYONE had expanded roles, which meant you had at least half a dozen people competing for the spotlight, costing real character development.
What the producers seem to forget was that while TOS was an ensemble show, it was also at the same time, not an ensemble show. You had three tiers of characters, Uhura, Sulu, Chekov, Rand and Chapel were the third tier; the supporting cast. They'd occasionally get a larger role, but they were rarely, if ever, the main focus of the episode. The next tier you had was Scotty, important, but still not quite first tier. Then you had the trio - Kirk, Spock and Bones, the main characters. They worked so well because each one worked well against each other. McCoy was the emotional and instinctive character, Spock the cold and logical and Kirk reconciled both mindsets. The current films seem to just be concentrating on Kirk and Spock's friendship, when the friendship between Spock and McCoy is being ignored (and there was a friendship, it was just vitriolic).
Don't get me wrong, I like the reboot films, but they seem to be missing the point of the trio.