"I guess that it just seems to me that with the Air, Apple was more concerned with the rather arbitrary title of "world's thinnest" and ignored some very important issues about functionality."

Their design goal was to build the laptop as thin and light as possible. Things like an internal optical drive and removable battery didn't fit with this. It's not unheard of for optical drives to not be included in ultraportables. Of course, none of them spent the time to think up and engineer the ability to borrow another machine's optical drive. No doubt the Dell's of the world will 'innovate' this soon. Also, you can actually find an Apple store if you're having a problem and am in a hurry. The same can't be said for a Dell, HP, etc.

For many people, it is rather uncommon to put an optical disc in and I'm sure that Apple did their market research. The only thing that generally travels with me is a power cable and rarely used USB key. I don't both with extra batteries.

What causes these 10 page long threads is that this is not for everyone. I've seen PC people get openly pissed off that Apple didn't put a removable battery in this.

The WSJ article does a good job of explaining the device. You'll still have plenty of PC people attacking the thing without understanding it though.