With the Horford injury decimating Atlanta's frontline, now might be a good time to cash in on JO and upgrade our backcourt. Hinrich is out until February, but when healthy he's a significant upgrade to Dooling and Bradley (our two weakest rotation players) - he can shoot, run pick and rolls, defend both guard positions. Most importantly he can play effectively with Rondo and fill in for him as a competent floor general. Collins is a solid option as a 3rd string center: can't do anything but play physical defense and set screens, but reliable in those areas. We'd start Wilcox and bring Stiemsma or Collins off the bench as the 4th big depending on the match-up.
The Hawks can get away with Dooling as a back-up PG with T-Mac and Willie Green in the 2nd unit. JO gives them high quality rim protection and post D, and his weaknesses (rebounding, speed) are less pronounced with Smith (speedy team defender) at his side and Zaza (excellent rebounder) behind him.
Of course this is contingent on JO viewing the Hawks as a worthy destination, as the deal falls apart if he prefers retirement.