I believe the above poster is right, I think just as the original imac did away with the 3.5 inch drive (which was a pretty big deal in 96) jobs seems the optical drive eating dust. But I think it is a bit premature, apple is uniquely fortunate that they make there own software and could, I suppose, make everything digital (and make third parties do the same) but people still like burning dvds and CD's and while it may be decreasing, if apple was to sell it optical drive-less, and its billed as a premium notebook is should IMHO could with an exterior matching unit to give the purchaser the choice of lugging it should they need it, I would purchase such a notebook with that kind of included attachement.
smaller (and thinner) is better, and 90% of the time I dont need my optical drive, usually data transfers are either wireless or usb, i wouldnt mind bringing with me a thin discrete, aluminum
drive for those few times i require it, wouldnt hurt if it was blu-ray either