I agree that a fully-functioning visual editor with feature parity to WordPress would be great to see. In fact, I would like to see it be made a very high priority as forum users certainly have come to expect a WYSIWYG editor. To me, this feature trumps any other as it has the greatest effect on users and their ability to post.
Either the problem is difficult to fix or the main developers do not agree a great visual editor is very important because it has been disabled by default since April, which surprises me a bit. When it initially was disabled I figured it would be a temporary thing and would be back for 2.4, and now work is being done on 2.6 without mention of this. :/
