Hey, Veinticinco, I don't know if you saw the recent thread about the scam email some folks received with a photo of a black Air? I posted a comment where I basically said that I thought it would be a fabulous idea and that perhaps it could be a limited edition(although perhaps being put into production for a set period would work better), and I even playfully suggested that they could then call it the MacBook Rare!
Fun to let one's thoughts run away with themselves every now and again!
As to a black anodised finish showing white(or 'bare')metal underneath, I don't know anything about the actual processes involved, but I have a black iPod classic 160 and the lovely front(anodised?)panel of black metal was recently slightly damaged when I dropped in onto concrete. The corner of the black metal was 'dinked', so that it looks as though the metal edge has been flattened a little, kinda 'stretched' out a millimetre or so. However, it is still only black metal, even though the finish has obviously been far more badly damaged than anything a mere scratch could accomplish.
So, maybe a black finish wouldn't be a problem in that respect.
Anyway, pie in the sky I suspect. There's about as much chance of seeing a black MacBook (R!)Air as there is of seeing a 30" iMac, a matte cinema display or the MacBook Pro specified to match Tallest Skil's wish-list!
One thing superbly illustrated by this thread is the passion that we all share for the Air. It really is a breed apart.