I'll take a _wild_ guess here that at least the low-end revision of the MacBook Air is going to be a product that is intended to replace the "spot" in Apple's product line that the MacBook occupies now. We are going to see a RAM-based "drive" instead of a hard drive, and we're also going to see the elimination of the DVD/CD drive, at least at "the entry level".
For a built-in DVD/CD drive, you're going to have to "go Pro" (a la MacBook Pro), just as you have to get one of those now to have firewire.
This also makes me wonder if Apple is working on some kind of "system software distribution scenario" that makes it possible to do system software installs/restores withOUT having to use a DVD drive -- either by way of the built-in SD card reader that the upcoming MacBook Air is rumored to have, or else via a diret download from the net.
We may see future versions of the Mac OS sold on SD flashcards as well as on DVDs. No reason why that couldn't be done immediately, as many newer Mac laptops already have the card reader on-board.
