The E5200 based DVR server is looking really good. With the 2 hard drives, it idles around 50 watts and gets up to about 90 watts playing a 1080i HD stream in SageTV through the onboard graphics. During playback, it used about 30% of 1 CPU. That means there's plenty of horsepower for it to do much more. I'm planning on moving SqueezeCenter and MediaNet over to it, but neither of those is CPU intensive. I need to see what other functions I can move over from the HA server. The cheap AirLink gig NIC works great. I was able to sustain 400 Mbps transfers between the DVR & HA server.
Update: I just purchased my SageTV license and 2 HD Theaters.