Nice! Looking good. The dialogs aren't mega-snappy, but a lot better than the old editor. And look: you can click insert image/hyperlink and paste right away, without deleting the http bit or having to manually set focus to the textbox. Perfect.
Also: whoa, the editor grows!
Thanks for the server downtime message. It's weird how just a little line of text explaining what's going on makes finding the site down a lot less annnoying.
Slight error: the tooltip for the insert emoticon icon doesn't have a description.