OS.js Version 2.0
andersevenrud.github.io
andersevenrud.github.io
Canonical use something similar in their Ubuntu online tour: http://www.ubuntu.com/tour/en/
I like the idea of having a desktop available to you wherever you are. This could be really powerful as browsers get faster and stuff like webGL gets popular. 90% of the native apps i use like mail.app, iTunes, sublime text, git client, terminal, all that might as well run in the browser today. No need to save, just leave the app running.
I often work from home by VNCing to my workstation at the office. Because I live close this is actually very smooth, but a no go when commuting because of high latency. I'd imagine browser based apps might provide some buffer to fix that.