Do users of the MBA really need high power and super speed? To me the speed point it's at should be plenty fast, I'd rather keep a slower processor and get more battery life.
I don't own a MBA though so this is all just opinion. But, no one ever complains about too much power...
Price, batterly life, speed, and lack of ports is why I chose the macbook over the air. I mean come on 1.83ghz core duo? My 2 year old Dell that I just retired due to failing CD drive and a cracked LCD had that. But then again, I just bought my wife a mini with the same processor

- a step up for her, she don't need power; as she doesn't run what I do. But then again a baseline mini with the applecare, iwork, and an apple keyboard was under $1000 (including my state's sales tax).
But seriously if the Air got a speed bump, and added 2 more USB and was only around $1400 or so with a standard 160gb drive - then maybe worth the price.
Apple keeps bringing all their lines close together, I mean if you really look at the specs (other than ports and the video card) - how much different is the new Air, the macbook, and the MBP. I can't see all the price differences between virtually the same machine.
I think more and more people will still choose the middle of the road macbook due to it being the best price that includes everything. But - just my opinion.
Air - to expensive, too few ports
Pro - not much different than a macbook.
macbook (top of the line white) - best choice for money (I would not pay extra for black - I just covered my white with an incase to protect it and got the keyboard cover with the black keys - looks pretty sweet).
what I think Apple should also do, is drop Applecare. I mean really. why make people pay for it. Just change the standard warrenty to the 3 years.
But I know someone in the insurance business, who's done a lot of research warrenties are set at a point of time just shy of when the thing will standardly start to fail. i mean if something standardly fails at one year, then the warrenty is usually 90 days or 6 months. All the extended care warrenty does is to compensate the company up front for something that will fail eventually - in the hopes that you do not do not keep the item for the full term.
One good note is that Apple atleast allows you to transfer that warrenty, should the item go to a new owner.
My friend got swindled by Dell. He bought second hand machine that had an extended warrenty. It broke, and he went to use the warrenty and was told - sorry extended warrenties are only valid to the original owner at the time the machine was sold new, extended warrenties are not transferrable.
He through the laptop away, as repairs were going to run him over $600 on a year old machine. A new comperable machine was only around $700.