Say it ain't so.
Who is a Celticsblog legend.

It's really hard to say who will be back.
I think that Bradley will be shopped, and that Ainge will look to trade one of Sullinger or Olynyk (preference to trade Sullinger). Those guys will only get traded if it's possible to make a significant move up in the draft, or acquire an established talent with higher upside.
I could see Bass or Jerebko coming back, if one of the Sullynyk pairing is traded and the team doesn't draft a replacement. Then again, it'd be unsurprising to see both sign elsewhere.
If the team wants to make use of its cap space, or there is a trade opportunity for a guy with a larger contract (e.g. Gallinari), Wallace will be gone.
Evan Turner, I think, will be very expendable, but his trade value is likely negligible, and whether or not he stays will probably depend on who the team adds on the wing this off-season.
Pressey could easily get cut if the team drafts a point guard with upside beyond 3rd stringer.
Gigi will likely become redundant if the team acquires any wing players, but he might stick around as a 3rd stringer if the price is right. He could also go back overseas.
I believe the team will re-sign Crowder unless somebody makes him a ludicrous offer. Even if it takes 5 million a year or a bit more (i.e. to match MLE offers), I think he'll still be around.
The only players I am confident will be here in 6 months are Smart, Thomas, Young, Zeller, Crowder, and one of Sullinger and Olynyk.