The Ubuntu project has just released the second beta version of Ubuntu 12.10 (Quantal Quetzal) which is on track to release a stable and final version of Ubuntu 12.10 in early to mid October.
With this release, Unity Desktop was updated to version 6.6 and it’s one of the most visible changes in this beta version.
For a more detailed and technical information about this release, click here.
ISO images (32bit & 64bit) of Ubuntu 12.10 can also be downloaded from this page.
Finally, as with all beta releases, you should not install on production or mission critical systems. That’s because they are not fully tested and not ready to be used on those systems.
The current stable release for Ubuntu is 12.04.1 LTS.
Again, here’s the link to download.