No they won't as it's done to prevent grey imports. Games being much cheaper in the US (depending on the exchange rate) are cheaper to import than to buy locally. I did this with Nascar and saved over £500.

I have heard of them helping out (for instance) service personnel who take their games abroad and was told by a source that there is a key combination to turn this from US to Europe (but can't substansiate that). maybe someone need to disassemble the OS...