The VoIP & Gadgets blog has a great writeup on the release of Asterisk 1.8.0 today, including an interview with Digium product manager Steve Sokol and highlights of the new features in 1.8.
It turns out I was wrong about 1.8.0 RC3 having the ability to connect to directly to Google Voice, but this feature made it into the 1.8.0 final release!