This is an issue that will need to be addressed as we become a global economy with people traveling across national borders for business and tourism. The Internet can reach destinations in any country ... why not the apps as well?
Max, this happens since day one. What people (well some people) do is subscribing to several app stores (in several countries). This is really annoying, and I'm sure it is a negative point about Apple's app distribution model.
It is probably linked to how the app developers are paid, regarding income taxation, copyright and local content censorship by different national content regulation bodies.
Anyway, it sucks.
I think this has something to do with copyright. I have tried to download podcasts from the BBC as well as streaming content and it doesn't work. Much as I enjoy blaming Apple, I think it is the BBC's take and/ or British copyright law.
I don't know much about it but appears to be based on your IP address. Netflix has a different content for Canada because of copyright rules. I have been told there is a way around it by faking your IP address.
I think you need a VPN client so your Internet connection will be "tunneled" back to the U.S from England (or vice versa). I just checked with Google Play, an Android App Store, and there are quite a few VPN clients out there. I don't know if these would be available for your iPad or not.
VPN's have become popular in China and other countries where content is restricted based on your location.
It's not just content either, we Aussies pay more for stuff in the Apple store. Even if you can use a credit card issued by an Australian bank (most banks have 'blocks' of mnumbers issued), you'll see the Aussie price, not the, say, US one. Although apparently AMEX numbers cannot be resolved to particular regions...
I have heard the availability of apps all comes down to your Apple Account (iTunes). For apps in the UK, you need a UK Apple Account.
There's a number of tracks that I would like to get but they are only available on the US iTunes.
Netflix works by IP address.