Missed the mark
The MBA is nice, but not realistic.
First, I think Apple missed the mark on this one in that they went for style, and threw function to the wind. Apple, historically, has been able to combine both, and on this one they went a little far ahead of themselves, and the market for that matter. I don't think the market, and average computer users, are yet at that stage where you can completely eliminate, or almost, all connectivity to your laptop.
One MR posted that we are squabling about certain features etc. etc. etc. and that we are not the target market. But my point is precisely that this product doesn't fit any one market, except for the gadget happy consumer, and the naive materialist. (wait.... maybe that is a viable market

haha)
Second, the 13" screen is too bid to for it's target market. It doesn't completely reach the portable market, nor does it reach the student market because of its size, and lack of functionality. (You don't have to take my word for it, but there are still thousands of people who use the optical drive in their notebooks on the go).
Finally. I used to work for one of the largest electronics retailers in Canada, and I can tell you from experience that the new HD they will be using, which is found in the 80gb ipods, is a pile of ^$%#. I can't tell you how many ipods we replaced on a weekly basis because of defective hard drives, and problems arising with them. It'll be interesting to see what comes of this.
So, a) missed the mark; b) screen too big; c) Iffy hard drive.
Although I do find the next multi-touch track pad amazing.!! well done on that front.