I can understand Kindle only being available in the US at the moment (though I would love one here in the UK) but why does a publisher have to have a US Bank Account. This doesn't seem to apply to Associates and it can't be difficult to send funds to other countries even if they are in dollar currencies. Seems unnecessarily restrictive.
I realized I didn't make myself clear. Picture this scenario. Somebody, anybody, opens up an Amazon account. They also open up a bank account somewhere that is not monitored by any oversight agency like the British or U.S. government. They plagiarize your book, upload it and reap the profits. Where's the oversight? Who is making sure the author is genuine? Amazon and Amazon alone. Got it.
While I'm not an Amazon representative, my training is as an accountant, and I believe I can point you in the right direction for an answer.
The answer has to do with US governmental regulations. Basically, a US bank account means that Amazon avoids having to deal with US government currency controls (transfers of more than $10,000 overseas must be registered, for example) and it probably also helps Amazon be sure that they are dealing with a legal US entity -- which simplifies the tax issues involved -- if over $600 is paid to someone, Amazon has to report it to the IRS. In addition, I'm sure that insisting on a US bank account makes Amazon more comfortable in case the account owner has attempted to defraud Amazon. Its much easier to get money back from a US account than from a foreign account.