Libreoffice is now available and installed easily for Ubuntu 10.10 and 10.04 by adding the libreoffice ppa.
The following steps allow the addition of the ppa and the installation of LibreOffice:
Warning: This installs from a ppa and not from the official Ubuntu repository, hence there still might be problems with either the software itself, or the installation process. The installation will remove OpenOffice.
Optionally OpenOffice can be removed with the command
sudo apt-get purge "openoffice*"