Some keys to success:

Injuries: Who gets hurt when? Let's try not to remember the 2011-2012 season which had such promise and drowned in a sea of injuries.
Chemistry: Every team has a chemistry of its own. Even subtracting one player, much less a star of Thornton's caliber, can change a team's internal dynamics.
Post Play: I expect Sheldon to be greatly improved with a year under his belt and I have high hopes for Whitman (but now I'm not sure how much his off-season surgery held him back).
Defense: A major disappointment last year. Can we find something that turns this into a strength? We seem to have enough disrupters on the squad that something should work.
Crunch-time Offense: What will we do for key possessions? Ask Prewitt to assume the Thornton role? Bomb away from 3-point land? Hopefully something better than those options.

(Regarding the offense, we have lived off back-door cuts and 3s. It would seem that we have some players like Prewitt, Tarpey, Dixon and Tot, who could flash low and post up smaller defenders. We haven't done that much in the past and I'm not sure why).