Ugh. I've worked with plenty of HTC phones, and let me tell you, even if gaming really did care, the HD2 and Touch Pro's graphics would be about the same, and they're both able to run about the same things. For example, the HD2 comes with Sense UI, the new TouchFLO home screen for newer HTC phones. My older Touch Pro can run Sense UI just fine, because it's depending on only the embedded GPU. Of course, the HD2 would be 2x faster if it had to depend on only the CPU, but it doesn't.
Because typing faster is totally the best loving thing you can do with a phone.
Still, the touch pro has a touchscreen, so he can switch between qwerty and swype if he wants to.
The Touch Pro has a touchscreen, yes, but you also need to keep into consideration that phone with physical keyboards are much thicker than phones without the physical keyboards. My Touch Pro is probably about 2x more thick as the HD2, but that's to be expected. Plus, the Touch Pro doesn't have a multitouch screen, like I've mentioned, which means that if a multitouch application gets released for Windows Mobile, you won't be able to run it on the Touch Pro.
So basically, this is what you get:
Touch Pro2: Physical keyboard, no multitouch screen, thicker
HD2: No physical keyboard, multitouch screen, thinner.
Also, like I've said, I'm not taking sides. I think that the Touch Pro2 and HD2 both have their goods and bads, they're both great phones.