For a ridiculously expensive price, there are companies out there that will paint your Macbook Pro whatever color you like (including black)...I've humored the thought before, but to be honest, I grew quite fond of the contrasting silver aluminum chassis with the black screen/keyboard buttons...and this was coming from a 2007 regular Macbook that was matte black (thinking that I would never like any other computer more than that one because I loved the color).
I don't think they'll ever offer it again like that, but i DO think you'll get variations in colors to the aluminum on the MBP's and Air's eventually (like they have on the iPhone now). If you release a dark hue MBP like the space grey iPhone, I'll eat that up like dinner!