a huuuuuge threat to come in, at best 3rd in the Leastern Conference? OK. I don't really see how they'll get better though. They have no lottery pick, and it's not like any of their current roster is all that good at anything other than defense. Their leading scorer comes off the bench. I daresay the Knicks will be better, assuming Lin returns. The Pacers will almost certainly be better, with cap space and lots of assets to trade or sign-and-trade.
The Celtics will likely get blown up, unless Ainge sees something really special over the next few weeks.