Rather than bury this in the recent "Rumor" thread, we can actually discuss facts now.
International is using AT&T (and its international partners) for wireless. Apparently the International customers will use a separate store, since there are less titles available (220k instead of 350k for US customers). Looks like the bookstore is English-language only, and supposedly it won't include blogs (unconfirmed).
$260 for the US version, $280 for the international. No price change for the DX.
Edit: Apparently it's only for sale in the US, and there's a $2 fee for international downloads of any ebook (including ones in your archive). So it may not qualify as a "UK version" yet, more an expansion of download capability for US customers....