I just received the Japanese Famicom GBA SP yesterday, and I must say, it's the coolest GBA I've seen yet. The pictures don't do it justice.
The Super Mario Bros and Donkey Kong cartridges are really cool too. From the packaging, to the cartridge itself, a nice little package. I doubt any of these will be nearly as cool if they ever come out here, but here's hoping. I know I'd be buying one if it had the gray/black/red color scheme of the American NES.
Money well spent, but not for the cheapasses.