Microsoft won't even let you move your X-Box Live account to a different country/region. My wife has this problem now since her Live account is stuck in Europe and there's just no way to move it to the US. This is extra troublesome on the X-Box since some games are region locked so she has to order some games from Europe.

I think there may have been some misunderstanding here regarding his App store account though; I also see a comment on his blog indicating this. I moved from Europe to the US and can't remember having any problems moving my account to the US. I can imagine that it's problematic to have two accounts on the same device though.