Paul Boutin in Slate reviews the new MacBook Air and notes that "in many ways, phones are now more powerful than laptops":
It's not like Apple is hesitant about getting its suppliers to engineer new parts—after all, the company coerced Intel to build a special, extra-small version of its Core 2 Duo processor that would fit inside the MacBook Air. It's possible that putting a cell phone inside the Air would mean lots of regulatory hurdles before the device could come to market. But it isn't a new idea. Lenovo, for one, has offered the option for years. And Apple has stuffed AT&T wireless access into 5 million iPhones, all of which are slimmer than the new MacBook. Would it really have been that hard to put a cell card inside the Air?
The new notebook is touted as the first computer designed from the ground up to be used wirelessly; but without 3G cellular or WiMax last-mile access, it's really just the first computer designed from the ground up to be used over Wi-Fi. Which makes it the ultraportable equivalent of the iPod touch.
That said, I doubt these limitations will last terribly long, and I also don't think the MacBook Air is really the ultraportable solution. I bet that in a few years, as the processor speeds at that size catch up, the MacBook Air -- or its innovations, like flash HD and a drop of the optical drive -- will simply replace the MacBook. There will be a different Pro desktop replacement laptop, and maybe some kind of third less expensive, portable device.
What am I saying? Steve Jobs is giving up on reading. Screw Apple.