Given the economy, is this a good time to start a professional photography business focused on photojournalism, not personal photography events such as weddings, etc.? Professional photo sales would be via stock photography distributors, business services, insurance services, etc.
Ed, the answer depends on the kinds of professional photographs you will be taking, your connections into your proposed distribution channels, and what your earning requirements are. Sites like istockphoto.com, which provide licenses for millions of stock images at extremely low prices, have put a big dent in traditional stock photography license fees. This prompted Getty Images, the largest of the lot, to buy istockphoto a few years ago as a bet against declining sales for their expensive stock images. The quality of images in these less expensive sites is fairly good so if your hope is to make money through stock images, you might find a tough market that generates very nominal income for you.
However, if your photographs will be from assigned projects, you stand a much better chance at earning decent income. Such projects are usually assigned by organizations based on your relationship with them. Contact magazines, ad agencies, and others who routinely outsource projects to local photographers to take pictures of people or events nearby. Create a web site and post your portfolio (you can use software to watermark your images if you are concerned about unauthorized use). You might consider starting it off as a side business so you can gauge the marketplace and your growth rate, then make it a full-time effort once you have established connections and can project your cash flow more accurately.