This has been demoed publicly before, so shouldn't be a big NDA risk. I just held a 4-way video conference using iChat on Tiger. It was pretty darned slick, and I think was only limited by bandwidth.
Note the cool reflections on the "desktop", and the viewing angles of the participants. Seems much more natural than just tiling a bunch of video views into a window... And you can add people to an open video conference just by dragging them from your buddy list into the video window. Slick.