WordPress 2.7 is a complete rebuild. Not only on the inside but the outside too. 2.7 brings a lots of changes, the biggest one is a complete overhaul of the dashboard interface. Instead of having navigation elements on the top of the page, everything is now on the left side of the screen, similar to most Web mail services and Google’s home page.

Here is a quick look at some of the changes.
httpv://www.youtube.com/watch?v=dyVDsTAduiY