She may be on the promotional material, but in the films themselves she's unprofessional, doesn't have a consistent character trait and is overall useless.
Her only contribution is the only one of all the cast of characters that is done off screen and it's Kirk who makes use of what she did rather than her stepping up and taking action like everyone else.
I honestly don't understand how anyone can think of her role being better and more important than the original Uhura. In some ways it's worse because she's never at her station when a communication's task is needed (Kirk tells Chekov to hail the Narada), even when it involves the survival of six billion inhabitants of an entire planet that only has minutes left! But that's ok, you go ask Spock where his folks are. I'm sure that was way more important.
If Uhura is going to become a part of the big three, she needs to be in a position that reflects it. Not reduced to the same role she had in the original series where it's reduced even more. She did nothing in this film that would qualify her for a telemarketer post let alone a spot on a starship. She's useless, her station is useless and the writers think that's genius.
One of my hopes for Trek09 when it was announced was that Uhura would become the First Officer of the ship. Makes sense considering that Kirk and Spock love to go down onto the away missions together, and Spock doesn't need to be a first officer to be a big contributor.