The folks at Metasploit have announced the release of Metasploitable, a virtual machine that is pre-built with holes, missing patches, and vulnerable applications which can be used as test targets for Metasploit attacks.
Many Metasploit users run their own virtual labs with various older versions of Windows for easy testing and practice. This is usually time-consuming to set up and maintain, especially when you also include Linux distros.
Metasploitable is an Ubuntu build, so gives many testers a new target to attack than a traditional Windows box missing a few keystone patches.
I wouldn’t be surprised to see this expanded further and used as the basis of a lab for training purposes…