Check in with the desktop community (JDS project, in particular); they have or are planning to integrate a VNC server (Vino) into Solaris, but I don't recall whether that includes a client, and if not, then whether they have plans for one. If they don't, then come back and ping us again, but here are the contributor guidelines:
http://opensolaris.org/os/project/companion/contributors/
Danek
