September 30th! If this protocol catches on... being open like email is... it could revolutionize the web.
I've been watching this for some time, so it is exciting to see a date assigned.
If you have no idea what Google Wave and the Wave protocol is, watch the above video. Incredible stuff.
My favorite parts: Rosy the robot... the sample integration with a bug tracker and a blog... and the Initech wave client in an ansi terminal!