Well from all the hints that have been dropped, the 2012 event is definitely and finally the culmination of who and what Hope really and her Phoenix/Jean Grey connection. Its no coincidence that Mr. Sinister is coming back in the final issue of Uncanny just as the road to this event starts. Mr. Sinister knows more than anyone except maybe Cable and he is coming back by next summer for the final showdown.
We'll finally know who Hope is and as a result see Jean finally stepping outside the shadows, as she too has been involved this whole time. And it will all lead to the new direction for Astonishing X-Men (if not a reluanch), as the O5 band together one more time for the X-Men's 50th anniversary. What menace will bring the O5 together after all they have and why can't no one know about it? The one threat who single handedly hurt mutantkind the most, Cassandra Nova!