Essentially, one of the big differences between in-camera and lens stabilization is the stabilization of the image reaching the viewfinder. With the lens stabilization, you see the effect in the viewfinder. Not so with the body-stabilized cameras.Originally Posted by android17
Arguably, this difference is negligible at the shorter focal lengths.
When you're talking about 300 or 400mm telephoto lenses, it might make enough of a difference to a pro.
Furthermore, having the stabilization on the lens allows it to be 'customized' to suit the lens' characteristics.
Marketing and pride has probably prevented Nikon and Canon from moving to in-body stabilization, at least for the amateur range. It (in-body stabilization) certainly seems like the better value-for-money proposition.