The Zune Marketplace and other music retailers and subscription services probably saw today's announcement and thought: "Uh oh, the party's over."
Except that prior to this announcement, the Zune Marketplace was 90% DRM Free (as of Zune 3.0) with the most lax subscription service DRM of any player. Granted they have less songs, but it's still something. Prior to this, Apple had the half-hearted offering of DRM Free tracks at a premium (iTunes Plus).
That aside, this is a monumental step forward in destroying DRM. Read between the lines though, they only got this because they allowed the Music Industry to jack up prices on MP3's at their own discretion.