a nikon D3s will just make me very sad....because it'll make me want one far far more!
I do a lot of video work as well as photo, and there are many things that I would do to have a decent video system inside the best professional camera body... yeah, a D3s with 1080p video (or higher? nikon could do serious damage to the red scarlet if they brought out a 2K camera, pronto... hehehehehe), and the same insane iso performance.... would have me scraping together every penny I could find in the world, selling kidneys etc....
there's no 'downside' to having video in a camera. - no extra hardware to go wrong - yet the price is a bit more expensive, however, they'd sell more so economies of scale would bring the price down again.... or you could get a
second hand D3 from people upgrading, who DID want video.... no way is having a button or a scene option or whatever for video going to damage your use of the camera in any way shape or form. And hey, just maybe, one time, you'll have a sudden, pressing need to shoot glorious, high definition footage
I would be surprised if a D3s does come out, though, the leaked roadmaps have hinted at a D700s, but never anything other than a D4 in 2010/11... and the D700s would be the same price point, spec etc as the 5d2...