Actually, there was a discussion back a while ago about this. It need not be clear, more likely a neutral grey or smoke color that would not change the color of the display, but would obscure the board behind it. See this for more information. I would personally like to see these as well - I think it would match my dash better, but I haven't heard anything more lately.

Paul G.
SN# 090000587 (40GB Green)
_________________________
Paul Grzelak
200GB with 48MB RAM, Illuminated Buttons and Digital Outputs