The New Scientist just posted a quick video preview of Twine to YouTube. It only shows a tiny bit of the functionality, but it's a sneak peak.
We've been letting early beta testers into Twine and we're learning a lot from all the great feedback, and also starting to see some cool new uses of Twine. There are around 20,000 people on the wait-list already, and more joining every day. We're letting testers in slowly, focusing mainly on people who can really help us beta test the software at this early stage, as we go through iterations on the app. We're getting some very helpful user feedback to make Twine better before we open it up the world.
For now, here's a quick video preview: