[Kombisaurus]

But there's plenty of unoriginal subjects to photograph -- landscapes, sunsets, flowers, abandoned buildings -- what happens to the photographs that might be technically good and aesthetically pleasing, but aren't an original though?

I would argue that it isn't the subject that makes the difference between bad art and good art (or original/unoriginal art for that matter), its the message and how its communicated.
It is the idea behind the photograph that's important (to me anyway). The subject, like the camera, is really just the medium.

And for those photographs that are aesthetically pleasing and technically good, yet might not be good art - well they can certainly still have merit. While I might argue that aesthetics have no bearing on what I consider to be art or not, I'm not saying that aesthetics aren't important. There's plenty more to life than just art. Good aesthetic design and decoration are important parts of life that are often snobbed in discussions about art.
Ask yourself this... would you rather live in a home filled with tasteful, beautiful colours and designs, or one filled only with ugly, bad art?

I remember reading a quip that subtle theological questions are the least important, because they'll all be answered for me once I'm gone. Perhaps the question of whether I'm an artist should await the same resolution, leaving me free to take pictures until then.

Beautifully put. We simply are what we are.

And finally, here's a link to an essay which I think holds the secret to becoming an artist...
http://www.luminous-landscape.com/essays/practice.shtml