Amazon has finally announced international support for the Kindle. They now offer the Amazon US & International edition for 279$ (available October 19th). It can be used in over 100 countries (using AT&T's global roaming network). Each download overseas will cost 1.99$ (when you buy a new book or download one from your archived items). This is rather expensive - so this is more for Americans who want to use this abroad as well, although it can be shipped internationally from Amazon.
The Kindle US edition now costs 259$ (down from 299$), and will not allow for international roaming.