btw, the wwdc videos have been public for a while. Take a look at them if you're itching for more infos: http://developer.apple.com/videos/wwdc/2010/
No official release date for the final release is known, but judging from Apple's history with developer previews you can expect it to be out within 6 weeks.
Not enrolled in the iPhone Developer Program? Learn More" => "[pay $99]"
So, not quite yet.