There is an extra charge of $2 per ebook for non-US customers (but then no charges per download) and the selection is limited by geographical restrictions in the contracts between authors and publishers. It is about the international K2 release more than a year ago, but see
International release of Kindle 2! for a country by country breakdown.
Note that you can open an account at amazon.com and then set your country for the Kindle store and see the ebook selection and price.