Ubuntu 10.10 Beta has been released yesterday night. Along with it, the betas of Kubuntu, Xubuntu, Edubuntu and other derivatives were also released.
This release includes a number of new features which will become a part of Maverick Meerkat when it is finally released.
If you want to test, here are the download links:
Ubuntu Desktop, Netbook & Server
Kubuntu (Desktop & Netbook Edition included in one ISO)
(This is not available at the time of writing this.)
Edubuntu (DVD only)
Ubuntu Studio (DVD only)
(Again, not available at the time of writing this.)