I briefly mentioned that my new Centris 660AV came with the new SuperDrive that doesn't do automatic inject, as the older SuperDrives did. In that respect the drive is more like the floppy drives on the PowerBooks. However, I find the ergonomics of the PowerBook drives better because the PowerBook drives are located on the side, making for an easier motion than pushing a disk in from the front.
Either way, it's not a big deal, and the new floppy drives do have one nice feature not shared by the older floppies. A major problem experienced by older Macs is that the floppy drive slot is used for ventilation, and the airflow through the drive slot resulted in dirty drives. The new SuperDrives sport a protective dust cover that should reduce the amount of garbage inside the floppy drive. The new drive is slightly larger than the old ones, so Macs require new front panels to accommodate the new drive. These panels resemble nothing so much as a pair of puckered lips, but the important fact is that you can't mix and match the old and new SuperDrives.
Apple claims that the new SuperDrives are functionally and electrically the same as the old ones (other than the manual inject and the dust cover), but Apple's rationale for switching is that Apple can more easily source the new drives, which means that the company can go to different suppliers to buy them, thus reducing the price and ensuring a constant supply. In theory this means Macs will cost less, but in fact it's more likely that Apple or the channel will absorb the difference in the ever-shrinking margins. Current model Macs made as of September, and all new Macs, will incorporate the new floppy drive.
-- Information from:
Apple propaganda