I think you need to ask B & H about the return policy. While Nikon is most certainly aware of the issue, whether they have made changes and produced bodies which do not have this anomaly no one knows. Since the camera has only been out for a few months I would not assume the bodies currently in the US are necessarily free from the excessive spots initially seen.
Spraynpray really has the best advice. If you are near B & H, they may clean the sensor free or a Nikon Service Center most certainly will. I can shoot 200 frames in an hour or two, and I might suggest you go out and shoot some images...about two hundred, then shoot a nice white piece of paper, underexposed by about 1-2 f/stops, focused on infinity and the paper about two feet from the lens. And at f11 or smaller. Look at the spots and see what you have. If there are a lot of spots near one corner, get it cleaned and see how it goes after this. Shoot with the highest FPS it will shoot (5 FPS I think) and click off about a hundred or so. Then do the white paper thing again.
The intent is to get past the oil/dust spot issue so you can go about your business and not worry about the issue.