Previous editions were somewhat challenged, but Windows7 is way better than any previous version wrt multiscreen. I run multiscreen with one framebuffer on my desktop and laptop and multi-framebuffer on my laptop with a DisplayLink USB frame buffer. It Just Works, including easily changing orientations, laptop disconnect/reconnect, changing to display cloning for presentations, etc. Windows-P is your new keyboard shortcut friend.
What pisses me off is that I hate Windows; But it does show that if you concentrate on fixing bugs, over time code can improve.
The sooner all the animals are extinct, the sooner we'll find their money. - Ed Bluestone