It takes away most of Amazon's competitive advantage and means other stores like Zune Marketplace and Rhapsody will need to scramble to get DRM removed from their music files as well.
This is great news. The Zune Marketplace has already made great gains in making their content available as MP3. You can check with Jason Dunn on this but I think the estimate is that about 80% of the Marketplace is already DRM MP3.
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