The architecture of the iTunes app store was created for tracks of music, and was based on rights management issues tied to licensing of the mechanicals, the words and the recorded works, which is why the iTunes store and App Store architecture is country specific. To gain access to a specific country's app store or iTunes store, you need a credit card in that country or you need to load the account with Apple credit That means creating yet one more account with Apple..Not something I want to do and between business and personal, I'm already getting confused.
But apps are different. Rarely is their licensing tied to countries, so unless an app developer only chooses to list an app in specific countries, it would show up in all. The rub though is with the telecom/mobile operators who forget the pre-paid market of visitors who come to a country with an unlocked iPhone, pick up a local SIM and then want to manage it from their iPhone or iPad, like I do.
In France the SFR app would very helpful to me, even with my limited ability to speak and read French. I can follow instructions. Same in the UK for T-Mobile or Three. The list likely goes on. All of this is rather niche I know, but for those of us who do know, and do use the iPhone and iPad when we travel, and go through the effort to become a customer, even for a week, it would be nice.