Now I still don't see many changes but the screencast of wordpress.com looks really fine. You can watch it here. The only thing I noticed is that my admin-theme "Leopard Admin" doesn't work any longer because of bugs in the design.
This article was written more than one year ago. The information in here might be inaccurate or outdated by now which means if this is an how-to or tutorial it might no longer work. Please remember that while reading the article.
As the new version of Wordpress was released today I've just upgraded my blog to the new version too.