By the end of 2012, I expect the war to be over. Basically, I expect Tobi's identity to be fully revealed, and for all the current battles to be over (Madara vs. Kages, 7SM, Naruto vs. Tobi and soon Kabuto vs. Itachi).
I don't know if the series will be over by the end of the year. Simply put, there is a heck of a lot of story left for Kishi to tell. Don't forget, that the war has been going for over a year now so its likely the loose ends won't be finished until about a year from now.
But I think that the fated naruto vs. Sasuke may not happen until after the war is over, but if it is part of the war, it will be the final battle and prlly wont happen until the end of next year at best.