UK gadget site Pocket-lint has word from Apple that 4GB, 4th Gen nanos were produced "in a limited number" for some international markets, but they were never on the overall product roadmap. Were they intended to hit Dutch retail, or only for online sales? Could be a shipping mixup, could be clearing out inventory, could be on purpose -- but perhaps a collector's item for US customers.
Now we have word from Dutch blog One More Thing that indeed the 4GB units are being sold, in all nine colors, for €119. Amazon's German site is also selling the units.
Engadget has a lovely gallery of the low-cap iPods up for your viewing pleasure.