Trying to come up with trades, that I think would be good value for Atlanta and that wouldn't severely affect Boston's title chances.
I think this is the best one I could do.
Bass, Lee, Sullinger, Melo, 2013 1st
for
Smith, Stevenson
Atlanta gets some nice rotation players on reasonable contracts, 2 young players, and an extra 1st. Not a great deal, but not bad and certainly better than Brooklyn's presumed offer.
So Boston post trade would be
PG - Bradley, Terry
SG - Stevenson, Terry
SF - Pierce, Green
PF - Smith, Green
C - Garnett, Wilcox, Collins
That team is closer to a title this year and has the potential pairing of Rondo and Smith to build around going forward (with Green being a nice piece). If Smith does leave this summer, then there is a good chance PP, KG, and Terry all retire, and thus Boston would have cap space and could go into full on rebuilding.