It seems to me that the iPhone probably had the highest R&D costs of any Apple product, and that they had to charge a premium price initially to make sure they would cover those costs. Once it became clear they would cover those costs, they could lower the price of the product dramatically because they only needed to cover the cost of parts and manufacturing going forward. When you include the R&D, I don't think they were making an outrageous profit on the early sales. Also, I think it was pretty clear from the beginning that $600 was a very high price for a phone and had to come down a lot as soon as possible to be able to compete in the phone market in the long run.
I believe that it was quite clear from the hype that surrounded it that they would cover their R&D costs. Heck, if they and introduced it at this price, the demand may have been even higher. I am willing to venture that a very large portion of their R&D costs went to the Multi-Touch interface. Since Multi-Touch is obviously intended to be used in more than the iPhone, why should they have charged their early adopters? They could have spread the R&D cost to the new iPod Touch as well. If it is as revolutionary as they say it is (and I believe that is is) then their R&D costs should not have been a big concern.