I have tried it many times, but can't seem to get it working.
What I am doing is creating two images, one of a 10GB disk and one of a net install ISO of Debian.
I set everything up (x86_64, boot from cd rom), novnc listening on 0.0.0.0/9999. The machine is listed as running with 0 KB but when I am trying to VNC to it from sunstone I keep getting:
WebSock error: TypeError: Cannot read property 'length' of null.
So in fact I think it is not working.