Kinotehnic (Kinotehnik - The makers of LCVDF and LCDVFE) has just announced a clip-on magnifying viewfinder for the rear LCD screen of the D800 & D800E.

This would appear to be a useful gadget when using live-view to focus Zeiss and other manual lenses. Has member tried one? Apparently they've been available for the Canon 5D for some time.