This looks cool but I'm not blown away by the ad on any level. I don't feel like I have a good idea of what sway is or does. Is it powerpoint? Is it for making websites? How did it actually help that guy make his octopus umbrella?
It looks like a combination of (social) search, OneNote & PowerPoint. It seems to let you find, store and organize information. Then you may also format it for presenting. That's what I got from the ad anyway.
When I first saw and started using OneNote it was a beautiful experience and felt so different from every other Microsoft product. So far, Sway could have that feel do if they do it right.