Even /if/ it allowed GUI access for roots via VNC, it wouldn't allow random toolserver users to use GUI based applications. In my experience, I've never seen anyone who would successfully set up a VNC session, who didn't have the knowledge /intelligence to be able to use an ssh command line.
The notion of per-user-seat licensing for DB access on per-user-seat-licensing Windows domain becomes (very quickly) astronomical. There are 273 lines in hemlock's /etc/passwd. Even if "ONLY" 200 or so of them had ToolserverDomain access...
...well, all notions of "small business" or MSDN subscriptions are obviously inapplicable. I don't know how many thousand's of dollars PER USER it would cost, but I would guess the licensing alone (PER USER) would be about $4, 000.00 US. (Plus the all the server costs.)
Tell ya what - pay me $4k for each user I teach to use X Forwarding + ssh...
Connel