GAH! How many types of DRM is Microsoft going to create here? The latest is "PlayReady", which looks to be intended to support a wide range of formats (from AAC to H.264 to, of course, WMA) so that companies can wrap pretty much any content they want in DRM - be it ringtones or video or whatever. It'll be (thankfully) backwards compatible with Windows Media DRM 10 (which should mean that PlayReady devices will also be PlaysForSure devices). Is this replacing PlaysForSure? That's unclear right now, but with the Zune already eschewing PlaysForSure, it definitely doesn't look to be long for this world.

I'm starting to think I'm going to need a spreadsheet to figure out which devices will play which DRM. I'd bang my head against the wall in frustration, but with the proliferation of DRMs coming from Microsoft, I'm not entirely positive I have the proper permissions to do that.

Wireless delivery of content to handsets continues to grow rapidly, underscoring the need for compatibility and interoperability. To address this requirement, Microsoft PlayReady has been designed to be fully backward compatible with Windows Media DRM 10, allowing devices that support Microsoft PlayReady to access content using Windows Media DRM. Microsoft will also provide an interoperability program so content may flow to qualifying DRM and content protection technologies.

Read: Microsoft Announces Breakthrough Technology Enabling Simple Access to Broad Set of Digital Content