Gnome Shell is the new project that is underway for the Gnome window manager (WM). Currently it is in a beta-type state but may be avaliable in either the new Ubuntu release or the one after that. (Below is a nice screenshot of it running on my computer.)
Several people (including myself) are opposed to the idea of implementing it as the default Ubuntu WM since it is quite hard to get “under the hood” of the system. I would not recommend it for business use but it’s kinda fun to play around with.
As you might be able to see from the screenshot, you can add or remove virtual desktops to create more space. One is also able to drag programs between virtual desktops. It is very similar to Compiz’s exposition effect. I might do a screencast of it in use for a better demonstration.