From http://www.kubuntu.org/news/kde-4.1:
KDE 4.1 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.
From http://www.kubuntu.org/news/kde-4.1:
KDE 4.1 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.