DivX is launching a hardware platform for a media streaming box with openness in mind. The set top box I was showed (a plain looking reference design) had HDMI, component, composite outputs and a b/g WiFi and Ethernet connections for connecting to your PC. The gorgeous UI I saw had PS3-like 3d thumbnails of videos and photos, and music can play in the background as you browse your albums. There's even a front page weather widget. And the whole thing is built on an open API so it should be fairly easy to add metadata or build plugins in a pretty nice UI.
Here's the interesting thing that keeps costs down — decoding of, say a HD DivX video stream is done on your PC and the decompressed (or partially decompressed) video is sent to the box. That keeps the cost of the box down, and although DivX wouldn't say how much the boxes would be when the launched in a couple of months, I'd guess that they'd be below $200.
Minimum requirements for the box are a P4 1.6Ghz CPU, with half a gig of RAM. More as we play with this thing.