I have heard rummers of this type of development project in the past years, but have not seen a good execution of the concept… until now. Take a look at the StartForce Web Browser-based Desktop.  You have to register for a free account which only takes abot 5 minutes. You have a 1 GB file storage and transfer quota with your account. There is a short video demo of this on CNET.

I never thought I would be using a web browser with-in a web browser baased desktop to be surfing the web. - http://www.startforce.com/