Just a few days ago, the fine folks at WordPress.org released WordPress 2.0.2. From the inception of this blog's current form I've been using 2.0.1, so this is my first upgrade. The directions in the codex are simple to follow and worked flawlessly. It was just delete this, that and the other thing, upload new files and I was done.
The directions remind you to backup your language packs if you're using WP in a language other than English, but they miss one vital thing. You should also backup your .htaccess file. Failing to do so will change things like the permalink structure and will break addons like Ordered List's Feedburner plugin.
Fortunately I thought ahead and made a backup of everything. The upgrade from 2.0.1 to 2.0.2 was painless and quick, but only because I took that extra step they didn't bother to mention.