Still waiting on the scrolling text bug that they introduced with the new UI. Chat windows can sometimes cut text off at the bottom, until you hit a chat key and scroll that window down. It also apparently affects the console, because the console no longer autoscrolls to the bottom anymore. I'd assume they are related.
Also, the old-as-fuck and annoying-as-hell hitframe issue with the demoman's sword/axe. Third person hitframe is at the very beginning of the animation--not synced up with the first person animation. As a result, the player sees his sword hit as normal, but other players get hit before they see him start to swing, and thus cannot react. Very fucking retarded.