Ubuntu 9.10 was released less than a month ago, however work had already begun on the next version of Ubuntu, Ubuntu 10.04 Lucid Lynx. Lucid Lynx is scheduled for release sometime next year, however, you can download the development versions of Lucid Lynx and try it out in your test environment.
Ubuntu 10.04 Lucid Lynx downloads are available for both 32bit and 64bit PCs. However, you might not able to fit the 64bit edition on a single CD due to an unidentified bug. However, you can still run Ubuntu Lucid Lynx using a DVD, USB Drive or Virtual machine.