It's all rumor and speculation, but a picture paints a thousand internet links. This alleged HTC Touch HD is a fullscreen touch device with WVGA (800X480) resolution—essentially taking, say, the Touch Diamond's razor-sharp screen and making it longer. As another metric, if you think the iPhone looks nice, realize that screen runs in 480x320.
Other specs include 528MHz processor, 256MB RAM, 512MB, HSDPA, GPS and just 12mm of thickness. It's supposed to be "in stores for Santa." [Modaco Thanks everyone!]
DISCUSSION
It's those non-subsidized prices that kill it for most. I spent as much as a grand for some of HTC's older incarnations, so having to pay half and dealing with the limitations that the iPhone had/has is worth it. Drop the high-price act and you'll find people will switch back faster than you can keep up production...