“The Air exists because there are a substantial number of people willing to pay a premium to get a lighter notebook.”

Agreed, though that specific segment is still a niche market.

“If Apple satisfies them with a lighter MacBook, they are leaving money on the table.”

That’s one way of looking at it.

But Apple just made the Air even more of a niche product thanks to the new lighter, thinner, aluminum 13″ MacBook. Where I had been near 100% certain my next Mac (to replace the three year old 15″ PowerBook G4 I’m typing this on) would be an Air with more storage and better graphics (which was delivered in the revised Air last month), now I’m on the fence between the high-end Air and the high-end MacBook. I’d guess many prospective Air buyers are in a similar predicament now.

While you’re right about the Air’s current target audience – fairly affluent buyers who are willing to pay more for less – the Air also has mainstream appeal, with its price being the major drawback. If, and again this is a couple years away, the price were inline with the new MacBooks, maybe $1400 at launch, it would broaden the Air’s appeal while still giving pleasing those looking for an ultralight laptop. The new aluminum MacBooks will undoubtedly cannibalize Air sales (if they haven’t started to already) and at the same time Jobs wants to kill off physical discs in favor of digital distribution via the iTunes Store; consumers want thinner and lighter laptops. Dropping the MacBook’s internal SuperDrive to slim it down would eat into Air sales even more, in addition to creating buyer confusion between the two.

What alternative do they have but to retire the MacBook and replace it with the Air?

“I don’t see how such a move would necessitate the production of an even smaller Air. Remember, before the Air, Apple was doing just fine selling the MacBook and MacBook Pro.”

The Air exists because there are a substantial number of people willing to pay a premium to get a lighter notebook. If Apple satisfies them with a lighter MacBook, they are leaving money on the table.

@Well-known naturalist with a local high school named for him

A 13.3″ notebook is a 12″ notebook with a wide screen. The current MacBook is less than 1/2″ deeper than the 12″ PowerBook. To go back to the 12″ form factor Apple would need to go back to a 4:3 screen on a new model, and either allow a model with a different screen DPI than all the current models (except for the special-order 17″ HD model) or try to find a market for a notebook with 1024×600 display. I don’t really see any of those happening for a mainstream notebook. For a NetBook, maybe. But Apple doesn’t seem to be interested in that market. Of course, they didn’t seem interested in the phone market either, until they suddenly were.

No no You’re forgetting the real reason the Air is 13 inch. Steve Jobs is yanking the 12 inch PowerBook crowd’s chains! The 12 inch or less Apple notebook is the new Newton.

My laptop? An original 2003 12″ PowerBook. Hypocrite that I am, I’d give it in for a new MacBook Pro if only I had the cash! 1024×768 is just a little more oldschool than the G4…

“I can see something like the Air becoming a future MacBook if Apple can figure out how to do it for $1,200.00.”

Hmm, how is that really different from what I’m predicting? The sentence that follows that is kind of related, but it’s more of a separate prediction. I guess I should have said the Air will replace the MacBook, though I was really envisioning a slightly (emphasis on slightly) more full-featured Air that adopted some of the MacBook’s features like an audio-in jack, better speakers (I believe the current Air outputs in mono), a glass, buttonless trackpad, and (perhaps) a black-rimmed, glass display.

But Apple wouldn’t have to get it down to $1200 from the get-go; the new MacBooks debuted at $1300 and $1600, the high-end config. featuring a back-lit keyboard, yet the lowest advertised price is $1000 because they’re keeping on the last generation, plastic MacBooks until they can drive down the cost of the aluminum models. Apple could repeat this strategy with the Air in a couple years, no problem, using the thicker aluminum MacBooks to present the appearance of a lower starting price.

I don’t see how such a move would necessitate the production of an even smaller Air. Remember, before the Air, Apple was doing just fine selling the MacBook and MacBook Pro. If they had wanted to go smaller, I believe they would have with the original Air, but they didn’t because computer screens smaller than 13 inches can feel cramped/claustrophobic.

“Why? What would keep Apple from introducing a hybrid of the MacBook and the Air in a couple years?”

Profit. Keeping the Air lighter and smaller than a MacBook gives people who value that kind of thing a reason to spend more money. That’s good for Apple, good for people who value the smaller and lighter computer, and good for people who don’t place a premium on that because they get to save some money.

I can see something like the Air becoming a future MacBook if Apple can figure out how to do it for $1,200.00. But I’d also expect to see a future Air that was smaller and lighter than that MacBook at a premium price.

Why? What would keep Apple from introducing a hybrid of the MacBook and the Air in a couple years? CD sales will be even more abysmal, burning CDs isn’t nearly as popular thanks to mp3 players (namely the iPod), and few people watch DVDs on their tiny 13″ to 15″ laptop screens. None of these tasks are generally done on the go at a library or coffee shop or friend’s house or out on the back patio. Why require people who have little or no use for an internal disc drive to pay for something that only adds bulk and weight? It makes far more sense to provide an external SuperDrive as an option for those who want or need it (as Apple already does with the Air).

“MacBook and Air are likely to merge in the next couple years as internal disc drives are dropped entirely.”

I don’t see this happening. I may not be anywhere close to the target market and you may only be a bit closer, but there are lots of people out there who do fit the Air and are willing to pay the premium price for it. Apple would be foolish not to take their money.