This year's breakout manga from Shonen Jump is Assassination Classroom, about a middle school class who have one year to learn how to assassinate their alien teach or he'll annihilate Earth.
The 51st issue of the 2012 run of the home of the home of Naruto, Bleach and One Piece went on sale November 19th and launched new series Novice Policewoman Kiruko-san. Immediate reaction suggests that it might be SJ's next hit.
From Baka Update's description of the series:
Meet the tiny police station of rejects, consisting of Kanjuurou the snide chief, Haruki the common pervert patrol officer, and Kiruko, the rookie policewoman… who also just happens to be an insanely strong former military mercenary!
Well, the series seems to have immediately won over a following... or at least its green haired heroine has.