Gnome 3.6 is scheduled to be out on 26th September and the Gnome foundation has released the second beta release of Gnome 3.5.91. However, they are in source format and compiling and testing them is a hard task for a desktop Linux user. The good news is, you can download an ISO of this release and test Gnome 3.6 awesomeness before its final release.
Matthias Clasen, member from Gnome Team says:
“They’re basically a debranded Fedora 18 desktop spin, and I think they’re looking fairly nice. We’ll try to refresh these for 3.5.92 next week“.
You can download the ISO from here and write it on a USB stick or on a DVD. Also, you can give it a try on a virtual machine.