Looks really good. I had high hopes for Bespin, but I haven't heard anything about that in some time, so I suppose I'll start watching this project instead. I know it's based heavily on GDocs, but my workflow is based around Dropbox. Maybe something could be rigged up there.
Bespin merged with "Ace" - the new project is at http://ace.ajax.org/ or https://github.com/ajaxorg/ace . As an aside, I was sad to see Bespin go. It used canvas for rendering, while Ace uses the DOM. While the Ace team had good reasons for this, Bespin just looked so.. pretty..
I didn't realize Bespin was gone, that's a shame, but it looks like they're making a lot of progress. Being in the process of moving from a (dying) desktop to a laptop, I appreciate things like Chrome syncing where I don't have to spend a whole day configuring my browser any more. I am okay with moving more of my apps to the web, assuming offline mode is always an option. I look forward to more "cloud" products like this.