The LibreOffice suite has more momentum behind it than OpenOffice.org and also writes to the .docx format natively. Here's how to switch out OpenOffice.org for a more regularly updated LibreOffice repository.
On a philosophical level, some users may want to get out from under the thumb of Oracle, which discontinued the openSolaris desktop project upon acquiring Sun Microsystems, and which may not have the most interest in continuing the OpenOffice.org project. On a more realistic level, with many of OpenOffice.org's developers having jumped ship to the team behind LibreOffice, and with better built-in support for the OOXML/.docx format that's (unfortunately) used by Microsoft Office 2007 and later, it could be a smart upgrade.
A reader points us to a blog post offering the proper terminal commands — just one or two of them, honest! — for replacing OpenOffice.org with LibreOffice. LibreOffice also offers Windows and Mac downloads, although in beta at the moment.
LibreOffice Now Available in ppa for Ubuntu 10.10 and 10.04 [txwikinger's blog]