G2 since it's stock Android and doesn't have some slow-to-update skin. You'll get upgraded to 2.3 a lot quicker when it comes out. I like updates more than video chat (which I would never use).
From the CNET reviews I saw, they said that the 800mhz rating was a bit deceiving and that the G2 actually performs really, really well... granted, that's only one review though.
I have the G2. First Andriod phone I've had since my iphone (had it for 4 years) Just as great or slightly better (except for gaming)
Different cores. The G2 has a newer model of CPU which is faster despite a lower clock speed. Clock speed isn't the end-all be-all in computers, nor is it in phones.
Same core clocked at different speeds. G2 can be overclocked so clock speed isn't a relevant factor. With that said I would wait on a better phone (Dual-Core)
The HD7 was released today. Played around with one at Radio Shack. Nice phone. Although I'm still gonna get the Evo (on the 20th....) finally....waited for my little sis' contract to end so I would open up a 2 line with sprint for $112.
I did this and love it after previously owning the G1, Nexus One, and G2. I'll come back to Android once theres a major jump which should be coming soon in the form of dual-core and Gingerbread.