I am not sure the ODD will be taken out... but I'd like it to. And there are quite a number of reasons why I think it might happen.
a) The success of iTunes: Apple wants you to buy your music through iTunes, and offers you a generally cheaper deal than what you get on a CD. Getting rid of the ODD is, in a way, forcing you to buy your music through there. More profit for them.
b) The Mac App Store: Apple saw the success iTunes has been, saw the success the iOS App Store is being... and decided to re-apply a clearly winning formula. This will satisfy the software needs of most of Apple's main customers: the Americans.
c) The Macbook Air: Apple said MBAs were "the way of the future", which might mean that soon their lines will adopt the "No Optical Drive, No HDD" philosophy.
And before you say MBP - ODD = MBA, don't forget the MBP has a whole number of features that the MBA does not have, in exchange for decreased portability: backlit keyboard, more battery, more CPU/GPU power (even after the MBA refresh that will be coming), lower price when compared to the same-inch-product. So no, a MBP - ODD isn't a MBA.
d) The redesign: it is widely speculated the MBPs will suffer a big redesign on next release. Aside from the possible usage of Liquid Metal / Carbon Fiber as materials I can't see much being changed, except possibly for an internal redesign. In the inside, I can see a much wider number of possibilities: the substitution of the HDD for SSD/Flash storage, and/or the removal of the ODD for a bigger battery/a dedicated GPU in the 13''/a HDD+SSD combo/a lighter laptop.
e) The way Apple supplied its software to the MBA: Apple cared specifically about not forcing MBA users to buy an external superdrive, and supplied a USB Pen with the OS.