Well, it's pretty clear that the Bush administration started the ball rolling on UBS, but it remains unclear to me what's REALLY going on.
I'm thinking it's the usual Obsessive-Compulsive government money collection types, but they really got undercut by the Obama administration with the Geitner/Daschle/Rangel/etc. nexus. Kinda of hard for the government to stand around beating its collective breast piously about "tax cheats", when half of the upper levels of the government are Tax Cheats.
More is going to come out - the thing to do is to watch who gets named as being a tax-cheat UBS customer, and who doesn't.