I own a domain name -- wemightneedthat.biz. I have other domain names; I have no real need for this one. I own it because ... well ... you get the idea. It was (and is) cheap to do so. I currently use it as a sort of an on-line junk drawer.

Adding video capacity to dSLR's isn't quite as cheap as a domain name, but I wouldn't expect it to add a lot to the per unit cost. Most of the hardware is already there. The software development costs, after all, are spread out over a very large number of units, and adding an extra connector isn't that expensive either. Nor would I expect it to add significantly to the weight.

I believe that as a rule, people make buying decisions based on emotion and then look for facts to justify their decision. Part of that justification, either to themselves or to their spouses, may well be video capability. After all, "we might need that."

Personally, I see the D800's video capabilities as a small feature at a small increase in price. If it saves me from being stuck in back of an unfamiliar video camera even once, it has paid for itself. But had the D800 not included video, it would have placed Nikon at a marketing disadvantage far greater than the cost.

If you want to photograph a man spinning, give some thought to why he spins. Understanding for a photographer is as important as the equipment he uses. - Margaret Bourke-White