My guess would be nothing probably happens before the season but look for the Cavs to try to acquire a center before the deadline.
Also, the Cavs owe the Celtics one for helping them clear the necessary cap space to sign Lebron.
They already gave the Celtics draft picks and Tyler Zeller.
Whoopdedoo
Joking (well, sorta.)
What I mean is, the Celts played a pretty instrumental role in helping the Cavs clear the necessary cap space to get Lebron by agreeing to that 3 way with Brooklyn.
Cleveland being able to send Jarrett Jack to Brooklyn was a huge obstacle that was overcome, but that deal doesn't happen unless the Celts help facilitate it.
For the love of everything, there were how many teams taking on salary for draft picks? Lakers did, Philly was willing to, Utah did last year and had the room to do so again, Orlando is still under the salary floor and was seemingly willing to, and I'm sure there were others. The Celtics were willing to take the least to facilitate the trade, which is why Zeller, Thornton, and a pick came here, but I assure you someone else would have stepped up to the plate.
Presumably the Celtics were willing to take less because they find Thornton more useful than teams like the Sixers and Orlando would, as while C's fans expectations are reasonably low, Ainge/Stevens aren't completely punting on the season.