OOO was given to the Apache Foundation and anybody concerned about open
source or free software licenses should be concerned by this. The Apache
license is not copyleft. Therefore it can become proprietary and be released
with no source code. This has fuelled a bunch of distros deserting the
OpenOffice ship (Debian being the most recent), so OOO future is not
assured. So while the differences may be slight, LibreOffice has the
momentum and open source community on its side.

If you want LibreOffice in 10.04 you might want to add a PPA to your
sources.

www.ubuntugeek.com/install-libreoffice-in-ubuntu-11-0410-1010-04-using-pp\
a.html