I just heard about the Global Cache (
[Link: globalcache.com]) product. It seems that it could replace a HTPC in my situation and would let me control my A/V devices with an IR blaster controlled over my wired and wireless Ethernet. I would have the GC-100 in the room with my A/V equipment and control them with a wireless PDA browser.
Not quite clear what software would make that work, but maybe Charmed Quark's?
http://www.charmedquark.com/