this will happen
as the g5 chip gets smaller and cooler this will happen probably by summer, they may even add better handles and more pleaseing front end.
i love two drives for duplicting cds dvds, coping files, and with newer software maybe writing 2 cds or dvds at once may be possible.
burning a cd while watching a dvd, the superdrive has a slow cd burn speed, you can pick up at light on 52*32*52 for $50 the g5 is so fast might as well get the fastest cdrw, right?. and when faster dvd r rwritables come out next year or the blue lasers disc, you can keep your combo or superdrive and just add the newer technology without external cases and wires and powerbricks. so for me imho 2 optical drive bays should be the minimum