If you look at Jackson's splits last season, he started out strong and slowly and consistently tapered off as the season went along. (hit .400 in may, .317 in june, .304 in july, .263 in August...you get the point) This makes me wonder if pitchers were figuring him out a little more as the season went along which would require some adjustments on his part in 2013. However, his runs, BB, and SO stayed consistent all year.
He also was 0-4 in 2012 attempting to steal on lefties and didn't reach on a single bunt. This would lead me to believe that he has to have a big lead to steal a base, hinting that he: a. doesn't get good jumps, b. doesn't really have the base running speed everybody hoped he would.
All that said, I think his floor of production for 2013 is: 98 R, 14 HR, 56 RBI, 10 SB, .270 BA
and the ceiling for his production for 2013 is: 110 R, 18 HR, 78 RBI, 16 SB, .305 BA
In most fantasy leagues, he'll get drafted higher than his numbers would suggest he should. He really only does 1 thing really good and that's score runs and I predict he'll show that again this year.