I remember iMav making a post about this many moons ago, but I can't find it. Are the keycaps from the original and newer revisions of the HHKB pro exchangeable?
Incidentally, I just got my Happy Hacking in today. I literally have only got it out the box, so it will take a little while before I will have my full opinion, but initally -
a) Bloody hell, this thing is small.
b) Topres are interesting. And nowhere near as rubber dome like as I was expecting.