MySQL Sandbox 1.20 was released yesterday.
The new feature, as suggested by Ronald Bradford, is the ability of creating a group of servers from different versions. So now you can have a group of N servers in a group, each one having a distinct version. The cool thing is that using the Sandbox built-in scripts you can send a command to all the servers at once, thus being able to check the answer from different versions.
Need to know more? I will be speaking about the Sandbox at the MySQL Users Conference and Expo. TODAY! 2007-04-16 at 10:50