KDE 4.1.1 has been released and packages are available for Kubuntu 8.04, the Hardy Heron. These packages install to /usr/lib/kde4 and can be installed along side your existing KDE 3 installation.
The fifth Alpha release for Kubuntu Intrepid is available now for early testers. This release uses .kde instead of .kde4 for KDE settings so you will be unable to easily downgrade to KDE 3. See the release announcement for more information or download it directly.
KOffice 2 Beta 1 has been released. Packages are available for Kubuntu Intrepid in our kubuntu-members-kde4 personal package archive.