From TrekMovie.com:
Will it fit with Star Trek History (canon)?
Yes.
The writer/producers (Abrams, Orci and Kurtzman) as well as star Leonard Nimoy have repeatedly said they will respect Trek history and canon.
Does ‘Trek canon’ allow for Kirk and Spock meeting before the Original Series?
Yes.
First it is not yet clear if the film will be set before the 5 year mission or not, but if so, there is nothing in established canon that would contradict meeting before.