I am pretty much in agreement with BarrieV. Sashihara is getting an incredible push, no wonder she will eventually replace Acchan as Team A's (and AKB48's) ace. I think she is the one who did best. Matsui Rena had a pretty good year too, Majisuka Gakuen shoot her up over 10 positions in the senbatsu, and she has appeared in several dorama episodes, plus Kareha no Station reaching #1 in the SKE48 set list. She has a great future ahead, even though she is older than most idols. Yuko had a great year too, #1 at the senbatsu, with Heavy Rotation sales (best-selling single until Beginner), dorama participation, etc.
Shiichan got it rough at first, but joining Team A, then the Shuukan AKB and Nemousu episodes about her pushed her popularity upwards. She was said to be the Amina of the 13th senbatsu, but she didn't explode. However, looks like administration didn't forget her.
For 2011, one must look at the youngest: Aamin, Suuchan, Wasamin and Komorin. I think they all will get great pushes as AKB48 starts to replace old blood with younger ones (I expect several graduations next year).