Oh yes, such a nightmare. I moved from Germany to the UK, 2 app store accounts. Then I moved from the UK to the US, 3 app store accounts. I am consistently switching accounts and accidentally repurchasing apps ever since. Luckily, it seems, that with iOS 6 at least you can update all apps, no matter which region they're from (how ridiculous that already sounds), without typing in passwords/switching accounts over and over again.