This is not a trade I want to do, but one which I think is a much more reasonable idea of what the Celtics can get in a trade.
Corey Maggette is a flawed player with a big contract who Ainge targeted as a possible alternative to re-signing Posey after 2008. The Bucks reportedly would like to get out from his contract, one which Ainge (rightfully) would prefer not to take on. Boykins, like Nate Robinson is an undersized guard who provides energy off the bench. He would be a back-up point guard contingency in case Delonte West gets injured again. Plus LA fans consider him to be a "Laker Killer". If Boston tosses in a draft pick (second round?) to compensate for O'Neal's expected lack of production, maybe Milwaukee would go for it.
Milwaukee gets to do a salary dump, but maybe they could get more from a team like Dallas (who reported have some interest in Maggette). Boston gets a good rebounding and scoring wing who provides needed depth at SF and who at least has the talent to play decent defense if not the desire, but he's injury-prone and overpaid on a contract that is too long.
I wouldn't make this trade and I don't think Ainge would either, but I think it is the level of trade that is available to Boston, one that could be but isn't necessarily an obvious improvement and probably involves taking on a bad contract. I don't think Boston will find any slam dunk obvious trades the team should make (with the exception of maybe finding a way to trade with Chris Wallace and the Memphis Grizzlies).