Upgraded to wordpress 2.2 a few minutes ago. Here are the steps:
Deactivate plugins.
cp -r diary diary_back
mysqldump [options] dbname |bzip2 -c > dbname.sql.bz2
cd diary
mkdir backup
mv wp-config.php wp-contents backup
cd ..
mv diary wordpress
curl -O http://wordpress.org/latest.tar.gz
tar xzf latest.tar.gz
cd wordpress cp -r backup/* .
open wp-admin/upgrade.php
change cat_id in wp-categoreis to varchar(255) instead of varchar(55) to fit my category names
I fixed the cat names
activate the plugins
All done!
Everything seems to work and it is still valid XHTML 1.1