this may shed some light on the whole process, and other celtics picks as well.
http://www1.realgm.com/nba/draft/future_drafts/detailedbasically, as i read it, atlanta can switch picks with brooklyn in 2014, which they would do if brooklyn's pick was better than their own.
if atlanta switches, then boston will get the atlanta pick instead of the brooklyn pick.
if atlanta does NOT switch, boston gets the brooklyn pick.
so, as long as atlanta stinks, the celtics are probably going to get the brooklyn pick. the fun part will be if BOTH brooklyn and atlanta stink. then the celtics will get a good pick regardless.