If you have not yet started the tutorial, click on at least the first one. It's snazzy the FireBug-ish console action they have going on there, and the Bespin/Skywriter editor action, too.
If this doesn't show what the next generation of web-app looks like, I don't know what would. It remains to be seen, however, how that model holds up to "real" work - which is the same concern I had about Bespin/Skywriter.
Actually, I think that's just CodeMirror, not Bespin/SkyWriter. It's cool nonetheless, but personally, I would like it if they integrated it with node+jsdom (or even more awesome would be hooking it up to an actual webkit/mozilla instance).
Something like this for personal/private data would be interesting too, a system for people to take their data out of the "walled garden" websites, possibly a browser extension that runs it passively, copying information whenever a user views it, storing it locally, to enable true data portability.
I like that concept in theory (as a passive browser extension), but it might be wiser to store it in a user-connected cloud-based account for security reasons.
If this doesn't show what the next generation of web-app looks like, I don't know what would. It remains to be seen, however, how that model holds up to "real" work - which is the same concern I had about Bespin/Skywriter.