Beta 2 of our 12.10 development version
is available for download and testing. It comes on larger 1GB images, and features the latest KDE Plasma Desktop and Applications plus new application selections like KDE Telepathy and Calligra Krita for painting and Kexi for databases.
12.04 LTS users should follow the upgrade instructions. The Ubuntu Technical Overview describes all the big changes and known bugs in the Ubuntu archive.