This is of concern to people running Intel Macs, PCs, or Virtual Machines.
As of May 23, 2012 the official version of Mint 13 is available from http://linuxmint.com. If anyone has the RC version, it seems to have updated successfully to the official version. The release comes on a single layer 800MB DVD. There are two versions at the moment. Cinnamon (a Gnome 3 fork) and MATE (a Gnome 2 fork). I have installed the 64 bit RC of Cinnamon and found it acceptable after installing various bits of useful software. Also, this release is a Long Term Support (LTS) release. It will be supported with updates for five years.
After a little more than a week of use I find it is acceptable on my machine. I have not tried it on any older machines yet.
The major advantage I found going from Mint 10 to Mint 13 is there are newer programs available in the repositories. I dislike the lack of options for panel configuration, but it looks better than Mint 12.