at least the MD formfactor is/was convenient, but the audio is coded with a lossy, proprietary ATRAC-3 codec. i don't trust codecs i don't understand ;-)
in my opinion, the market has to offer one non-lossy audio format. i cannot tell exactly why, but it's my deep belief.
i don't think the cd drives and players will vanish completely that fast. it makes absolutely sense to leave them out of some new computers, since they're not needed that much any more. the fact that apple is the first or the most radical one to do so does have, however, a different reason: while other manufacturers replaced cd by dvd and are now replacing dvd by blue ray (which can play audio cd as well as far as i know), apple does not. there's a licensing issue with the blue ray standard, so apple hardware can not, as far as i know, play back video blue ray discs. i think apple tries to oppress the users crying for blue ray by marketing the loss of a optical disk player as a step forward in product development.
However other manufacturers will follow. There's a need for slimmer and lighter notebooks. But i think there'll be the option to get an external drive for a long time. Even today you can easily get a usb 3.5" diskette drive.