We are not used to such surprises! Same day with the release of Gnome 3.6,we also get a Live Media to try it out! The image is based as always in the next Fedora release -Spherical Cow.
Although there are many Live CDs of Distros that ship Gnome 3.6 by today, Gnome Live Image offers the most genuine experience with all modules to the latest versions.
Nothing to say, see for yourselves!
If you want to install it you can try:
Of course there are more options, I am just mentioning the two I use. Ubuntu Gnome is almost stable, when in Fedora you should expect some hard times :)