The only difference between US, Japan, and the rest of the world is the number of available channels (11, 14, 13 respectively), so technically you could update to the US driver to obtain WPA2 support.

could be some form of export restrictions.   more likely it's just dell being slow to update

Thanks, guys. I wondered about possible export restrictions, and it's be nice to know if there are any. That said, from a technical point of view, the US wireless regulations are the lowest common denominator (in that other regions have the same channels, plus 12, 13 and 14), so I'd be surprised if running with the US driver contravened local regs.

I may give it a try. In the meantime, it'd be helpful if Dell pulled their finger out and produced a 'kosher' European driver.

There is no export restriction on WPA2 as far as I can tell.  Many brands ship their wireless network devices with WPA2 support outside of the US.  It is much more common for the brands and manufacturers to release the US version first and the European driver much later (sometimes never).  That said, the Intel OEM driver for PRO/Wireless 2200BG adapter that I downloaded from Intel US includes support for WPA2, plus 13 channels for ad-hoc networks!