Especially by actually showing the NX-01 (model) and firmly establishing, without any doubt whatsoever, that Enterprise
really is the last remnant of old Trek in this universe
(Oh, and old Spock. I liked Nimoy's cameo.)
I didn't catch the NX-01, but what really bugged me is that there was a model of the Vengeance on his desk. Wasn't this ship supposed to be a super secret warship? On the other hand, the base where it was stationed didn't seem exactly hidden or even guarded.
Nimoy was the only true surprise in this movie, and a very welcome one at that!