I’m primarily a GNOME user, but I was interested and followed along with the development of KDE 4.0. It’s time to start testing again now the KDE 4.1 Beta 1 has been released.
KDE 4.1 is the first major feature-update to the KDE desktop environment since 4.0. The Plasma desktop shell has been greatly improved and can now be easily configured. The KWin window manager supports more fancy features, including wobbly windows. More KDE applications, including the KDE PIM apps, have been ported to KDE 4.
The KDE 4.1 packages for Ubuntu are not ready yet. Until they are, you can run it in a virtual machine. The KDE4Daily virtual machine image can keep itself up to date with the very latest KDE every day. You can download the VM on BitTorrent. The download size is 700 MB.