The way things are going, it seems unlikely there will be many careers outside of art, photojournalism and fashion. Photographs are always going to be a tough sell in a gallery. If we're talking about it as a "business", then I'm not at all interested in something like that, and don't consider that real photography. Weddings, stuff like that, I'd rather not, thank you. No amount of money is enough.
You can't put commercial artists in the same hat as gallery artists, and photography is no different. One group works to make images expressly for themselves and on their own terms, the other group works to express the images for others in exchange for money. Leave all that to the soccer moms w/ DSLRs that someone else mentioned, and yes, those amateurs are hurting commercial photographers.
Besides, if someone is getting into photography these days w/ business ideas, they probably need their head examined.