It’s supposed to be released with WP 3.5.
YOu can get a test copy if you like, I’ve been playing with it on my test install….
— I believe it is available as an option on wordpress.COM now….
I’m referring to this page: http://make.wordpress.org/core/2012/09/20/timeline-for-twenty-twelve-1-0-final-testing-window/
I’m patient though, I can wait. π
However, I am curious. If I download the current build of 2012 will it automatically update once the official 1.0 is launched?
The main wordpress.org SVN server is/was undergoing maintenance today and the Twenty Twelve release has been delayed until after that work has been completed.