No sooner had I assembled a mini home theater PC for the TV room, but Amazon Vine offered me a Zotac MAG HD-ND01-U which is basically the same thing in a more appliance oriented packaging.
The guts of my original HTPC will now be moving into the house's new Linux/MythTV server: add a large hard drive, a cheap DVD drive and a larger case. This is going to save me a lot of electricity. A Pentium 4 is a pretty poor choice for a lightweight server, and is now draining over $10 of power a month; the new Atom based server should draw less than a third as much energy and maybe less, as I'm hoping the more modern design will have better idle characteristics. I'll save quite a bit of money in the long run in mothballing my old Dell. And the new Atom/Ion motherboard should be fine for serving the occasional file and recording TV shows.
2.0 GHz Pentium 4 + hard drive + external hard drive = 110 W (or so) at idle
Atom N330 + laptop drive + sleeping hard drive = 25 W idle
If I pay a dollar for ever 10W per month then I'm saving around $8 a month or $96 a year, so the added $180 I'm spending will be paid for in 2 years (or in 4 years if I had had to buy a motherboard and RAM). And I'll have a quiet server that isn't annoying me constantly with its fan.
[Update: It's so pleasantly quiet in my laundry room today. Just have to migrate the svn server on the little NAS to the new server and it's going to be so peaceful in the basement.]