WARNING: Manually disable all your plug-ins before attempting the automatic upgrade to WordPress 3.0.
Otherwise your blog will die painfully. If it’s too late, do a manual upgrade install (copy all the files via FTP) and then do an automatic re-install to clear any error messages. You may have to delete a file called .maintenance to get access to your blog after a failed install.
Been there, done that.
Eh, WordPress is a PITA all around. I jumped ship, I think it was 2.7.x. Things work so much better when your blogging platform works for you instead of against you.
Joomla, now that was a platform I had to fight tooth and nail. WordPress is a piece of cake.