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
http://releases.ubuntu.com/10.10/
Kubuntu (Desktop & Netbook Edition included in one ISO)
http://releases.ubuntu.com/kubuntu/10.10/
Xubuntu
http://cdimage.ubuntu.com/xubuntu/releases/10.10/beta/
(This is not available at the time of writing this.)
Edubuntu (DVD only)
http://cdimage.ubuntu.com/edubuntu/releases/10.10/beta/
Ubuntu Studio (DVD only)
http://cdimage.ubuntu.com/ubuntustudio/releases/10.10/beta/
(Again, not available at the time of writing this.)