Paul,
yes, there is a mish mash of court decisions on the subject. The case im refering to was a fed court case about a painter that paints alabama football games and players. he used his own money $400k to take it all the way to the circuit court.
a photo is considered fine art as an "item of commerce". in other words selling a photo you took is your right as far as selling the photo as an "object of commerce", the content is irrelevant, unless it contains something that is copyrighted. A statue for instance. that would be a copyright violation. A photo of something trademarked is treated differently. the photo is yours and you are within your rights to sell the photo or print of the photo itself. mass producing an image of a trademarked item such as posters,mugs,tshirts is not considered fine art. and would generally violate the dilution part of the protection.
In one case a court defined "fine art" as art created for having aesthetic, decorative, collectable value, and not used as advertising. (not exact quote here)
think of a line of photographers all photographing the same scene or object. each holds the copyright to their image. the image itself, as an object, not the content of that image.
Ironically, copyright protection laws were not written for artists and creatives. They were written to encourage scientific study to find new drugs etc.., by protecting a private scientists data from being used in others research.