Even with the iPhone, carriers have the final say. If AT&T doesn't like an application, it can just ask Apple to remove it from the AppStore. Or, they could jus

Even with the iPhone, carriers have the final say. If AT&T doesn't like an application, it can just ask Apple to remove it from the AppStore. Or, they could just block the network access that the application needs to work (e.g. blacklist websites that the application contacts). It is true that the iPhone doesn't come with vendor customizations, which is nice. However, none of the AT&T phones I have purchased have been extensively customized either. Most prepaid phones are subsidized by the carriers that distribute them (e.g. AT&T GoPhone), and those phones are locked to that carrier and have customized firmware. In the US, there are very few OEM phone sales. That is why you only see Nokia stores in the very biggest cities here (Chicago, New York, LA); I don't think there are any Sony-Ericsson shops in the US at all. OEM phones just don't sell.