I upgraded to WordPress 1.2.2 recently, so I built an RPM for the new version:
RPM: wordpress-1.2.2-1.noarch.rpm
SRPM: wordpress-1.2.2-1.src.rpm
These RPMs were built under Fedora Core 2 Linux. I have not tested them with other Linux distributions, so they may or may not work in those situations.
As is standard process, I recommend you back up your database and all your WordPress files (especially index.php) before upgrading, as described in the upgrading instructions.