In my opinion, they eliminated CD's way too early. While they may become obsolete in the future, it's no where near the point where we don't need CD's. While doing this they also increased the dependency the MacBook Air had on other laptops to perform routine task.
The fact of the matter is that once the MacBook Air's "coolness" wears off it won't become practical.
Just wanted to come back to this point. Reminds me of when I first thought of buying a Mac, I was thinking they were crazy for having just eliminated floppy drives. I mean, what the hell? People didn't do everything by CD! CDs cost too much, and had too much space for simple tasks! People NEEDED a floppy to move everyday files!
Turns out, I was a whole lotta wrong. IIRC, the 3-1/2" disk made its overall exit from both PCs and Macs over the next year or so once Apple eliminated it from their line. Turns out, people could use email to transfer files.
I'm not suggesting that DVDs and CDs will ever go completely away. Heck, burning DVDs is one of the things I need my new MBP for.
I just know that when I went to install my printer on my shiny new MBP 2.5Ghz this weekend, I had to go
online to download the drivers, because the disc Lexmark included with my new printer only supported up to Tiger. Most of the software I buy these days I download, and it's a lot easier than working via disc, anyway. I've used my DVD drive less and less over the past few years, and as video transfer goes more and more digital, I can see myself only needing it for rare occasions in the future.
But of course, that's just me. YMMV.
Still, I think the lack of an optical drive is not a big thing at all, and maybe even shows foresight. Only time will tell.