Hmm, if you can get VLC running on the PSP then you sould really be able to stream to the PSP.
You will have to have "WinGrabTV-0.05.exe" running on the PC, then use VLC on the PC to stream the output of WinGrabTV to the network in a format that is recognised by the PSP VLC. I have used the above method to stream Dbox over the internet in a Widows Media format.
I'm gonna give this a try, and feedback if i get it working, just need to find a PSP streaming video player if i cant find the VLC for PSP.