What hurt the team last season, in addition to injuries and underperforming, was lack of depth.
Diaz and Solarte are now the back up infielders instead of Goins and Barney. Hernandez (if he doesn't win a spot) and Alford will be in AAA for outfield depth instead of Coghlan, DSJ, etc. Jansen and McGuire both on the 40 man and could serve as depth instead of Maile and the platter of crap the Jays rolled out at back up catcher last year. The Jays appear to be covered to where they won't be rolling out below replacement dog s*** if someone gets hurt, and that's going to be a big step forward.
Of course the rotation could still use some work. Starting Biagini in AAA would be a good move to keep him stretched out and ready. The Buffalo rotation could be Biagini, Borucki, Upper Deck, Guerrieri, and maybe Pannone. I mean it's not great, but the Jays had Latos, Tepesch, Lawrence, Rowley, and Valdez start games for them last year. That's about as bad as you can get.
I think they are a 2nd wild card possibility. Not on the level of the top 4 teams in the AL, but could realistically fight with the Angels, M's, Rangers, O's, Twins, etc, for the 2nd wild card.