I thought I read in an interview with Abrams that S and U's relationship wasn't romantic until that scene on the ship in the elevator thingy(whatever it's called). He was emotionally vulnerable from seeing his planet destroyed and his mother killed so he was more willing to except...comfort from Uhura. It may just be the fangirl in me, but I'm hoping they continue this relationship in the upcoming films. I think it could be interesting to see what effect it would have on the character of Spock, and I'm not exactly sure, but from what I've seen of TOS they never really had any ongoing relationships did they? I agree though, I prefer the S/U thing in the context that their relationship was platonic until the events of the movie changed it to a romantic one.
Cassy, I don't remember ever reading this, but it doesn't mean JJ didn't say it. Do you have a link?
The way the actors played it, it seemed to me that they were already lovers...or certainly IN love with each other, requited or otherwise. The scene in the shuttle hanger certainly implies a sexual relationship. Also, their interactions and body language in most scenes seems to support a serious relationship(e.g. as Spock hurries from the bridge to beam down to Vulcan).