French Gadget Site GeekInc, got an early HTC Touch HD unit to play with, and took a bunch of pics to show for it, including a couple of size comparisons against the iPhone. As you can see, they're pretty much the same size, save for some backend tapering. Their own impressions more or less coincide with our own hands-on, in that TouchFlo was super smooth, the screen was huge, and it appears the Touch HD camera handles low light pretty well. Check out a few more images below, and for a bunch more, check out [GeekInc].
According to every site it's slightly thinner than the iPhone 3G at just 12 mm compared to the iPhone 3G's 12.4 mm. So thinner with a slightly larger screen, better camera, and higher resolution.
I like WinMo so it's all good for me. I like the iPhone too, without it kicking every other company into high gear to make better devices and UIs we'd still be dealing with crap.