I'm very keen to see an Apple take on Nettop/ULC Laptop. I think the Air is a fantastic product and an important part of the product matrix (And let me make this clear, the Air is a portable iMac), but it does leave us with a problem.

The Air is the portable iMac, as I've said. That makes the MacBook the entry-level Mac notebook, the portable Mac mini. That's flagrantly wrong. Apple is missing a cheaper notebook, a MacBook mini if you will. The current trend towards such devices gives Apple a perfect opportunity to make such a device. The components are now fairly commodity but Apple can leverage their iPod line's massive use of Flash and iPod classic's HDD to make those components even cheaper (Economies of scale).

Thus, Apple can compete on price, or else make the device more desirable (Easy enough for them) and charge a premium (I can see it starting at the same prices as the Mac mini or nominally, say $50, more)

This same product matrix issue solution creates another problem which has finally brought me around to the "xMac" standpoint. The MacBook would have no desktop equivalent. As such, Apple would be wise to introduce a headless Mac with some expandability. Likely this would just be an iMac without a display, just the MacBook is very similar to iMac's portable cousin MacBook Air

I should also add: I would buy the Apple 10" notebook to replace my Eee PC. A teeny laptop with the power of OS X is too much to resist.