Frankly, I haven't needed an optical drive in a laptop since booting from USB drives became practical a few years ago. (happy MacBook Air user here)
It'll be interesting to see if Apple fleshes out its Cinema display into a combined docking station and screen using the Thunderbolt port's potential. Add a DVD drive, HDD for Time Machine, USB/Firewire controllers, ExpressCard slot, whatever, using the PCIe channel in the Thunderbolt.
I see where you're standing. But actually I receive two DVDs per week in my mailbox, so last time was today. And I still buy CDs, yes.
I think what you really want is the next iteration of the Air with whatnot is missing from the current model.
The only situation where I could imagine an external CD-Rom to get in the way would be for watching DVDs on the go. But afaik even for that most people copy the movie to the harddrive beforehand - to prevent the drive from sucking the battery dry while watching.
I see the MBP as a laptop to use plugged in a socket and with a lan cable at home, work, a client's place or a library, and only need decent portability and battery life. For all other uses I'd prefer the ipad or the Air(wish I get the $$ for it).
Do I use it as often as I did, say, 10 years ago? No, but I can imagine why Apple would leave it.
What they really sacrificed here was the opportunity to make a compelling product. It's 2011, when have you last time used an optical drive?