Not that (I hope) anyone will notice, but I am in the process of upgrading my WordPress site from version 2.0.10 to the latest, 2.3.1. To the end user, there should be no noticeable difference.
I am taking the cautious route, as I advise anyone with a website to follow. First, back up the entire site, including the database tables. Then if you have not been staying on top of software updates do the upgrade in stages. Check to see if everything works before proceeding to the next step.
For WP, the upgrade is generally troublefree. You overwrite the old files (except wp-config and your theme files!) with the new ones. Any database upgrades are handled by the new files. If only php-nuke and Joomla upgrades were as well organized …
I started first with 2.0.11, then with 2.1. Everything seems to be OK, so I expect to finish the next two steps, 2.2 and 2.3, in the next few days. If the site looks funky, you’ve probably caught me in the middle of an update. Just come back later.