64 Studio is a collection of software for digital content creation on x86_64 hardware (that's AMD's 64-bit CPUs and Intel's EM64T chips). It's based on the pure 64 port of Debian GNU/Linux, but with a specialised package selection and lots of other customisations. It will be marketed to hardware OEMs in the creative workstation and laptop markets as an alternative to the 64-bit version of Windows XP, or OS X on Apple hardware.
You can download the ISO via http here.
Better yet spare their server and use bittorrent. LinuxTracker has a torrent available for this iso. Check here for more details.