I'm convinced that on these new anyone-can-make-an-app platforms (e.g. facebook, iphone, android), your best shot to make money is to be one of the first out with a product, then with that experience go freelance.

The markets become saturated too quickly. After a while, your problem becomes advertising rather than product quality. The only way I see to survive somewhat reliably later on is to diversify and become a portal/aggregation company.