* I've settled on the AppleTV because it's $99, so not much of a loss if it doesn't work out.
* Most of my videos are already in an MP4 compatible format already DVD->Handbrake->Apple Universal preset.
* It's dead quiet, no moving parts, no fans, and 6W of power.
My problem with the HTPC is it was a full Windows stack so it included all the headaches of antivirus, updates, configuration, and UAC prompts required a keyboard be nearby.
I can certainly see why some people have the inclination to go with a HTPC but I don't have the time nor the space to keep PC in the living room. And now, XBMC has been ported to the AppleTV so you get most of the functionality of the Windows application on an inexpensive device.