What? Unless the entirety of your information about the AppleTV comes from Cory Doctorow posts, you know that the only places DRM comes into the picture are when streaming pre-existing content from premium sources (iTunes Store, Netflix, Hulu).
There's absolutely nothing stopping you from loading a DRM-free h.264 file on another one of your Apple devices and streaming that over AirPlay. And HTML5 video in Mobile Safari works beautifully.