Don't expect to make a lot of money, at least not in the first five years. My first suggestion would be to actually work in a bakery to see how things are done. That way you can determine if you even want to deal with it. Long hours? Plan on being there 99% of the time, especially in the first several years. Plan on working every holiday, or at least pulling all nighters the week before a major holiday. It's hard work and I'm sure it's 100000% more difficult today than it was 25 years ago. It's a lot more than just making cute little things and putting them in a case. It's dealing with paying the bills/overhead, paying employees, insurance, oh yeah, and paying yourself. Don't forget managing inventory and book-keeping.
TV has really put a strain on bakers in general. I freaking can't stand all these cake shows where they have all these insanely outrageous cakes and they don't show the prices people are paying for these things. Duff has a $1000 minimum, and that was about four years ago when I last checked. It's probably higher now. People want cakes that do dances, fireworks shooting out of them, fondant sculptures of themselves, and, oh yeah, they only want to pay $20 because "it's just flour, eggs, and sugar," and they can get the same thing at Wal Mart. That's where your business plan comes in. Market to higher income clientele to avoid customers like that. The other thing that hurts bakeries are home bakers who have no idea what they are doing or what they are charging. They are low-balling everyone without even realizing it, and hurting local businesses. These people have no idea how to price and they are essentially paying customers to take cakes from them. Granted, these folks don't stay around for long, but more and more pop up every day so it's always something to contend with. One Wilton class does not a cake artist make. You have to be strong on both the baking/decorating front AND the business front. First and foremost, you need to be a business person or partner with someone who knows how to run a business.
So, get yourself a job or internship and see where it goes from there. If you really like it, you might consider taking some basic business classes at your local community college so you can familiarize yourself with that side of things if you don't already know about it.
Good luck in your venture!