Happy owner of a white HHKB here. Nope--PBT keys stay nice and clean. I've had mine for about four months and it still looks pristine. Supposedly, the ABS spacebar will eventually get shiny, but that's why I participated in the PBT HHKB spacebar Massdrop. :D And I normally get everything in black, but the HHKB looks really, really sexy in non-printed white.
Awesome, glad to hear it. I've actually become a lot more open to the idea of getting a white HHKB recently and that was the only thing I was worried about.