The real question is: how does app development on the iPhone compare to it on competitors (Twitter, Facebook, Web, etc.). It stacks up very poorly (in general of course) by almost every metric compared to the last two. I'll be able to tell you about #1 in a couple months.

If your goal is to leverage your programming skills to make money (be it millions or thousands) and work from home, you're going to find much more success elsewhere. If you want to make cool mobile devices that run on a popular smartphone, you won't.