I like the concept. The mockup to which you linked is a bit confusing. I think a box explaining that it is read only would be nice. (it actually seems more complex than that, I had an entire virtual machine to play with but it reset the hdd image on reboot.
<a href="https://github.com/virtkick/virtkick" rel="nofollow">https://github.com/virtkick/virtkick</a> is an empty repository. Am I missing something?