The title alone makes me scratch my head in wonder. It's like me deciding that I want to become a carpenter, but I have no idea what to build. Then again, I tend to have too many ideas that I work on, which can create its own set of problems by dragging my attention in too many different directions at once.

For the smaller developers, they should focus on something that interests them and which they personally find useful. Otherwise, if you are just looking to make money, there are plenty of companies out there that will pay you to program some boring internal application for them.