Region coding is different than NTSC/PAL. NTSC and PAL different ways the image is sent to the screen. The chip should work for any PAL imports in your case. And i think there is a simple way to convert from NTSC to PAL, but i'm not sure. Someone should test the chip on a EUR Wii before you buy one.
As for it being upgradeable via dvd. Doesn't that leave the chip open to be messed with by Nintendo? Technically, they could reprogram the chip to no longer work. Or, even worse, they could program it to mess up the drive in some way that you can't use the wii anymore, and then your system is no good and you voided the warranty by putting the chip in, leaving you with no choice but to buy another. Or maybe i'm paranoid.
I like the idea of getting a pic programmer and putting the hex code on myself and installing it, then whenever i need to upgrade it, i just reprogram/program a new chip (not sure how that works yet).