I was speaking to a hiring manager the other day (not for my self but just because he's a friend) and he told me that half the people he interviews tell him that they want to do iPhone development. What is really funny about this is that the company he's hiring for has absolutely no need for an iPhone application - something that should be obvious to anyone applying for the job.
Anyway, if you are dreaming about creating iPhone applications for a living you should check out the list of things you should NOT do when submitting iPhone applications to the AppStore. The list of "do not"s are covered in a two part article (Part 1, Part 2), "Avoiding iPhone App Rejection From Apple", by Bloggle With Harish.
In some ways I'm glad to see Apple filtering the applications that can be downloaded from AppStore. If it was an open system without review I would be a lot less likely to download arbitrary applications. The "Big Brother" aspect of Apple's review system does bother me to some degree - but not that much.
The iPhone and AppStore is Apple's platform and if their semi-closed garden is an issue than the market will punish them for it. Besides you should have seen the how difficult it was to develop, get accepted, and distribute mobile applications before Apple introduced the iPhone - now that was a closed garden!