I don't believe thats the culprit here. The iPhone 3GS is practically at the end of the product lifecycle and given the recent leakage of the next generation iPhone, that just boosts the effect seen here in these charts. It logically doesn't make sense for anyone to purchase a 3GS with the new iPhone just around the corner. It defies common sense...When the next generation iPhone is released, these numbers are not going to be the same as we see them here.
Finally, someone with common sense. Lol at people thinking this is a win for open source. It's only obvious people are just waiting to buy the next generation iPhone.