Subsidized prices and carrier signals
@Robert Hill - You're possibly right, but there's another possibility you're missing: the fundamental rule of price & demand in free market economies. Right now, Apple tell you that the iPhone is worth 600-700 Euros, but they're "nice enough" to sell it to you for a subsidized price that's easier to swallow for the consumer. But, just because Apple tell you the iPhone is worth 600-700 Euros doesn't make it so; in fact, it's actually worth the subsidized price because that's the price at which most people are purchasing them. Now, if subsidies cease, and Apple raise the price to 600-700 Euros how many people are going to buy those iPhones? Certainly not as many as would buy it at the lower, "subsidized" price... but, certainly, some still would because it's an Apple product and namebrands sell. However, I believe it's equally possible for Apple to instead be forced to sell iPhones at the previous subsidized prices due to concurrent lack of demand.
@Brett Brennan 1 - You certainly pointed out an issue between CDMA and GSM carriers, but isn't it possible that it would force manufacturers to produce products with both CDMA AND GSM receivers? AT&T isn't the dominant provider in every market, and I don't think many manufactures would risk losing out on good customer markets because of different carrier signals. Now, it's true that they could manufacture two handsets, one with GSM and one with CDMA, but it would be vastly more cost effective to produce one product with both receivers coming standard. And, in that case, it would only increase competition between all mobile companies as they're no longer fighting only for the hippest, newest product, but for total market share.