Plenty of fans have been understandably getting a bit wound up about the Bucks' thorny luxury tax situation and the likelihood that it would cost them the chance to retain both Ramon Sessions and Charlie Villanueva.  Which is why sending RJ to San Antonio for the useful (and expiring) Kurt Thomas and the partially guaranteed deals of Bruce Bowen and Fabricio Oberto is basically the best thing John Hammond could have done--especially given the difficulty of dumping salary during the season.  Sure, the Bucks won't be better immediately for this, but RJ wasn't an elite talent and the Bucks' trio of Bogut, Redd and Jefferson wasn't going to make them contenders anyway.  Any deal that allows them to get younger and more flexible salary wise is a good thing.  In any case, I'm not in a position to complain since I supported this exact trade on April 30:

Now, the easy answer is that they messed up [in not trading Jefferson at the deadline], and dealing RJ now probably won't help as much as it could have four months ago.  Maybe you can get the Spurs to send Bruce Bowen and Fabricio Oberto's non-guaranteed deals plus a rotation guy like Matt Bonner (or better yet, Kurt Thomas), but in general it doesn't seem like Jefferson will have much value given his inflated contract. Otherwise you're pretty much stuck taking on equivalent salary (maybe saving a couple mill) for players who will either be no good but expiring or decent but on longer deals.  And even if the Bucks dump Jefferson for expiring deals, it won't really pay off until next summer. 

Obviously, the deal works because the two teams are looking for very different things: the Spurs want a chance to make an immediate run for the title, while the Bucks need financial flexibility to re-sign Ramon Sessions and perhaps Charlie Villanueva.  Out goes Jefferson's $14.2 million contract for 09/10 and in come Thomas' $3.8 million deal and the reportedly 50% guaranteed deals of Bowen ($4 million) and Oberto ($3.8 million). 

If Bowen and Oberto are cut (and owed just 50% of their deals), that means the Bucks would owe a total of just $7.7 million to those three guys--meaning their cap number would fall a full $6.5 million overnight (at least by my quick math).  Considering they were going to have $2-3 million under the tax otherwise, that's huge.  With that additional space they could sign Sessions and Ersan Ilyasova, or perhaps Sessions and Villanueva, depending on how much interest he gets in the open market.  They also have three new attractive assets that could be used in a bigger deal down the road, though I'd assume Bowen and Oberto get cut.  I'll have more on this later, but rest assured this appears to be a very good day for the Bucks.