I just upgraded to WordPress 2.3. Usually, upgrading wordpress is easy task but not this time. I met a lot of problems while upgrading to 2.3. I disabled some of plugins that use wordpress category table which removed in 2.3. Thanks for Tags, update notification, improved Tiny MCE editor and Pending review features implemented in WordPress 2.3. I disabled Sitemap generator, Ultimate Tag Warrior, Add META Tag plugin as a result.
p.s : I’m going to make two WordPress themes available for download soon.