"The news will likely upset a number of Microsoft's customers, who bought music from MSN Music before the company launched the Zune Marketplace and decided to ditch the old store. Microsoft's decision to turn off the MSN Music authorization servers serves as a painful reminder that DRM ultimately severely limits your rights. Companies that control various DRM schemes, as well as the content providers themselves, can yank your ability to play the content which you lawfully purchased (and now, videos) at any moment—no matter what your expectation was when you bought it. Some Major League Baseball fans learned this the hard way last fall."
I wouldn't trust anything from Microsoft where in order for it to keep working, it would have to phone home to MS DRM servers. MS will eventually shut down those DRM servers without giving their customers a solution to use their DRM'd products post-shutdown.