Hmm, why all the talk? VNC has to do bi-directional mouse/keyboard input for one thing and is designed for low encoding overhead (of the tiles). IMO this will result in low framerate. The scheme demonstrated on that N8x0 appears (or rather we were told this is how the transfer is done) to use rather high overhead mpeg4 encoding (which is ok if you have hw assist) then the decode is also very cheap assuming you have mpeg4 hw decoding. I.e. you can do high framerates assuming all the bits are in place.

That picture of a device on Flickr looks to have a usb input and a VGA output - USB-VGA adaptor? Like the thing the N8x0 has kernel drivers for?