Heavy lifting
Of course the Air is fine for serious work, it is not a netbook but offers similar oomph as desktops did not too long ago. Photoshop & Co will run just fine, and Java programming is possible, too.
For those willing to shell out close to and above 2K for a more portable laptop, more RAM would often be very interesting. And for some, 2GB will be a dealbreakingly little.
I expect that something like this happened before WWDC:
Steve: Phil, if you don't give me a little extra manpower, my secret iPad is not going to be ready by the end of June, and everbody will hate me!
Phil: Sorry, everybody is busy updating the existing portables...
Steve: Just give me Gary and his fire-brigade for a few overnighters.
Phil: But Gary is supposed to get done with the new revision of the Air!
Tim: Uum... I don't know how to break the bad news to you, guys...
Chorus: WTF?
Tim: There are some pretty annoying last minute glitches in the new functions of MobileMe. The guys are booked solid.
Phil: There, Steve! I told you that your 2lbs iPod would have to wait until next year!
Steve: Hrmpf.
Tim: But, but. What happens to the Air? Steve wanted to try his new Nano-DVI connectors on the new platform...
Phil: Stuff it. The hinges break anyway, and the form-over-function pimps turn out to me a much smaller clientele than initially expected. Tell people to buy small MacBooks. Hey, while you are at it, promote the small Macbook to Pro status.
Steve: You mean, accept defeat? No more airy hotness?
Phil: Hm, didn't we just plan to do the scheduled the cpu clock increase? Maybe we can sell this as an update?
Tim: This could work, but everybody will laugh at us!
Phil: Shuddup, and listen to the turtlenecks... Pimps got no brains. Just make it cheaper, and everybody will be happy.
Steve: Hrrrm. I will be back! Just wait!