I just upgraded to WordPress 2.3. When using Konqueror (my favourite browser) the comment approval is slightly broken (when I tag a comment as spam it usually just turns red and doesn’t disappear from the main Comments tab) and I have to refresh that window more often than usual to make sure I got the result I desired. Also the Sidebar Widget editing is totally broken in Konqueror, I guess I’ll have to login with Firefox to get the new tags feature working.
Also I have got a few WordPress errors about the table “$table_prefix” . “post2cat” not existing. The table in question doesn’t exist in any of my blogs.
So far this is the worst WordPress upgrade experience I’ve had (I started on 2.0).