This is merely a proof of concept, like running the NES emulator, though this one has much less functionality (due to the lack of a mouse, etc.). Nebula has written up a handy guide if you have a rooted Pre and would like to try it yourself. If you have any questions about setup, feel free to pop on by #webos-internals on freenode IRC. One thing that should also be noted is that the VNC app (like the NES application) is ran from your SSH connection and is not in any form integrated into the WebOS interface, though that could change in the future.
Still, it's a very impressive feat and really helps to show the strength and versatility the WebOS and Pre can come to represent.
From precentral.