The upcoming Ubuntu 12.10 which is referred to as Quantal Quetzal has just released Alpha 3. This Alpha release is not recommended to be installed on production systems. A production machine is a machine that you use to do work on and can’t afford to have it corrupted by unstable programs.
To install this release, click here.
So, if you have a test machine and wish to test out this release, download an ISO image from the link above and burn it onto a CD/DVD and install it.
Again, here is the link to download the image.