Is there any possibility for using VirtualGL/TurboVNC on Raspberry Pi?
Well someone would have to change the source code of VirtualGL/TurboVNC to use the Raspberry Pi's GPU. There are some projects floating around on the Raspberry Pi Forums. Currently it's not possible, unless someone changes the source code.
Normal VNC use If you just want to use normal VNC, as suggested in the first comment, then you can just use TightVNC. Here is a guide on how to get TightVNC working on a Raspberry Pi, do note though that you will not be able to use VNC to see anything being rendered by the GPU IE: Video playback, GPU games (Quake 3, PenguinPuzzle). Just thought I might add this section based on the first comment.