#D is great but it is still time consuming to create the original geometry and then set up the lighting conditions, do a render find it is wrong and do it again, and again some times. Also most of my 3D work, like Pixel Monkey said is then posted edited in
PS, often to blend back in and give it more reality.
What 3D does give you on top of hard to achieve effects, is the ability to change the lights later or the angle and render again, to set up the photo shoot again to get the angle change is now going to cost and take a lot of time.
Where I work we do this with vehicles a lot. Initial development is time consuming and costly but location changes and feature\accessories changes are the areas where the money and time are saved.
Sorry got a bit off topic.