This is a feature request for F18 anaconda (or post-f17). When VNC is enabled for installs, could they be enabled with the shared function? This would make remote debugging signficantly easier, where multiple people could be watching the same vnc session. It would also be useful in cases where you are trying to educate a new user (of Fedora) and could follow along. If the shared-by-default option is less desirable, then perhaps a command line option would be more appealing.
Posted a patch. I think it's worth testing in rawhide.
Patch accepted for testing on rawhide. Will be in the next build.