I recently upgraded my blog to WordPress 2.5. The manual process is real cumbersome. Today I came across few plugins which help in almost automating the upgrade stuff.
WordPress Automatic upgrade: As per description this plugin first takes backup and then upgrades. I didn’t try this one, though.
Instant Upgrade: I upgraded one of my blog using this. It doesn’t take care of backup but otherwise the upgrade was super smooth. Just few clicks and you are done.
Happy upgrading !