If you lack the wherewithal to afford one of HP's dandy new MediaSmart TVs, you can get the next best thing, a $US300 HP x280N MediaSmart Receiver for your plain old non-connected HDTV.
It runs HP's own MediaSmart interface and can download movies from CinemaNow (with help from a PC), but it also has a complete Windows Media Center Extender interface as well, connecting wirelessly to your home network with all flavors of 802.11 including N, plus it has HDMI and USB jacks. The Vista-friendly x280N handles MPEG-2, DivX, H.264 and WMV, plus MP3, WMA, WAV, and unprotected AAC. It's got a slot for HP's Pocket Media Drive for carrying video from your PC by hand, but the drive doesn't mean this thing can be a standalone DVR.
Here's what it looks like with open maw: