I suspect we could implement software using sd cards and do without the disc drives. I know it is really cheap to manufacture discs and put software and movies on them but I'd pay $5 even $10 more to have a movie or a program on an sd card if it meant i could get rid of the disc drive. Maybe the air will get an sd port. Think of how much easier it would be to stock movies in an sd format and how much less it would cost to ship! The media form factor will get smaller and if sd cards were implemented Blue Ray may not be needed anymore. I am not trying to ruffle the feathers of those who own Blue Ray stuff but honestly do we really think using the same form factor as what we've used the last 20 years is a good idea anymore?
Personally as a photographer i don't have a use for an sd card port but if used for the above I embrace it wholeheartedly!
You'd pay $10 more for a film on SD card? As for using the same form factor as the last 20 years, the car, keyboard, bed, pen, mug, knife, Bicycle, sandwich seem to be doing OK, so i think i can put up with a disc for a while longer.