Macworld UK reports that EMI is seeing an uptick in purchases from iTunes since iTunes Plus was introduced. For instance, sales of Pink Floyd's Dark Side of the Moon [iTunes Link] have increased 350% (we all know hippies don't like DRM. I kid, I kid).
The real question is whether the uptick in purchases can be attributed to the lack of DRM or the higher bit rate encoding? Either way, this is good news for those of us who welcome a world without DRM.