I had pretty well resolved not to prognosticate about what Apple might spring on us at MacWorld Expo SF this year. After all, the Mac Web is chock-a-block with Expo rumors and speculation already, so why add more guesswork? I'm also a patient soul myself about such things, and perfectly happy to wait and see.

However, an e-mail message I received this week from my cyber-friend Roger Born proposed such an intriguing suggestion as to what Mr. Jobs might unveil next Monday, that I decided it would make and interesting topic for a column, regardless of whether Roger's prediction is bourne out in the keynote.

What Roger proposed, and he says this is pure speculation based on "critical thinking," is that we should:

Look for Steve Jobs to introduce a new combined iMac/iBook in several versions. These will immediately replace the current iMac and iBook lines, which have now been delayed in the supply pipelines.

• One cheap one for students, at the current iBook CPU speeds, priced way below a grand.

• One built for great portability, at the current G4 CPU speeds.

• One bigger one built to replace your desktop computer, at 1.7 GHz CPU speed.

• All in white.

• Also look for a new G5 . . .( ! ! ! )

This is a lot more radical than what I had provisionally been expecting, which was new iMacs, probably with LCD monitors, and a substantial G4 Power Mac speedbump to 1 GHz + G4 chips in the Power Macs or perhaps even G5 processors. Given that both the iBook and PowerBook were upgraded in mid-October, and the PowerBook again with combo drives just before Christmas, I was not expecting any news on the portable front at all in San Francisco.

However, Apple's own unusual pre-Expo hype over the past week makes that scenario seem, well, pretty conservative. After all, Apple got slammed badly last July for supposedly underdelivering on community expectations, and they really hadn't hinted at a whole lot to begin with. This time, they're promising the proverbial sun, moon, and stars, so it's hard to imagine that there isn't something pretty revolutionary coming down the pipe next Monday, otherwise they wouldn't be sticking their necks out so far. How far?

Monday - "This one is big. Even by our standards."

Tuesday - "Count the days. Count the minutes. Count on being blown away."

Wednesday - "Beyond the rumor sites. Way beyond."

Thursday - "It's like a backstage pass to the future."

So, viewed in that context, what Roger has suggested seems at least plausible. Logically speaking, once you go to LCD screens on the iMac, the hardware distinction between it and the portable Macs is substantially diminished. Remember that the original Revision A through D iMacs were pretty much WallStreet PowerBooks in a desktop case with a 15" CRT instead of a flat screen LCD display. Of course, the iMacs had standard 3.5 in. IDE hard drives instead of the PowerBooks' more expensive 2.5 in. units, but neither machine had PCI expansion slots, expandable video cards, or more than two RAM slots. The biggest difference, engineering-wise, besides the necessarily different power supply configuration, was the CRT monitor.

So, an engineering commonality between the new iMac and Apple's laptops isn't that much of a stretch, or even very revolutionary, once you dial an LCD screen into the desktop equation. Indeed, I think such a blending of laptops and lower-end desktop computers is both logical and inevitable. As I have asserted for years, the PowerBook (and now the iBook as well) is the "logical Mac" for most people, with the higher cost of laptop units having been the main stumbling block to wider adoption.

However, that cost differential has been shrinking drastically over the past couple of years, especially with the introduction of the dual-USB iBook last may, and with the iMac presumably going to LCD monitors, which have been the largest single factor in the desktop-laptop's price spread, the gap will narrow further. While I'm doubtful that the distinction between desktop and laptop units would entirely erased in a melding of the iBook and iMac lines, it would become increasingly blurred.

A major factor in my partiality for laptop computers has always been their small size and self-containedness. I've always thought that desktop machines, at least since the original compact Macs, were just too darned big and heavy. Even the G4 Cube that I owned for a few months in mid-2001 surprised me with how heavy and bulky it was when you factored in all its peripherals. To me, compared with a PowerBook, even the relatively compact Cube was just too big and clumsy and complicated. With its external speakers and external audio amplifier, its humongous external power supply brick, as well as the keyboard, mouse, and monitor, it was anything but self-contained, although less of a lump and spaghetti tangle of cables than my mini-tower UMAX S-900 is.

It was about half an hour's work just to untether the Cube, move it and all its stuff from my office to the living room, and get it set up again. I can just carry the PowerBook without even shutting it off if I don't want to. If I want to work in another part of the house or even outdoors, with the PowerBook it's no problem. If the AC power goes off, as it is wont to do here in the rural hinterlands, the PowerBook lets me go right on computing as long as the battery holds up, with no worried about loss of unsaved data from unexpected power failures. The compact dimensions of a PowerBook also do you allow a lot more flexibility in terms of workspace, and your laptop workstation doesn't dominate a room. You are also not tethered to that workstation if you want to work somewhere else.

If nothing else, the Cube purchase confirmed to me that I'm essentially a PowerBook guy, and I suspect (although never say never) it was my last desktop computer purchased as a principal workhorse. I traded it even for a 500 MHz Pismo PowerBook in October, and haven't regretted the switch for an instant.

When I bought my first PowerBook home, little over five years ago, I was immediately blown away by the realization that this tiny thing (it was a PowerBook 5300, which has about the same footprint as the dual-USB iBook) was substantially more powerful than my desktop computer at the time (an LC 520), but weighed about 1/7 as much, and occupied a fraction of the desk space and cubic footage. Ever since that day, desktop machines have seemed to me absurdly inefficient, overweight, power-sucking, space-wasters.

Lately a similar revelation is evidently dawning on more and more computer buyers. The laptop is no longer regarded as merely a portable auxiliary to one's "real" computer, and unprecedented numbers of users are buying laptops as their number-one workforce machines, or their only machine. In Q4 2000 worldwide, notebook shipments grew 21 percent year over year, compared with paltry desktop PC growth of 1.6 percent. Even Mac community elder statesman SteveWozniak is a PowerBook/iBook guy. In the last Apple's sales quarter for which figures have been published, the iBook was virtually neck-and-neck with the iMac in sales volume, with the less-expensive desktop Mac edging the laptop by only a couple of thousand units.

Of course, a minority of Mac users, probably somewhere between 10 and 20 percent, really do need the slot and drive expandability and potential for more raw computing power that is provided by a big, desktop minitower chassis. No argument there. To my way of thinking, the operative paradigm should be, not: "do I really need a laptop?" but rather, "do I really need a desktop machine?" In any case, the iMac, which is the desktop we are principally discussing in this column, never has been very expandable -- actually less so than the PowerBook with its PC Card slot(s), larger array of ports, and from the 5300 series until the TiBook, its removable module expansion bay. No iMac as ever had PCI slots. The only reason the iMac had to be so big and heavy was that 15" CRT.

In a recent column on OS Opinion earlier this year (unfortunately, the link I had no longer works), Dave Ficks observed that:

"The entire paradigm of how computers are used is changing, and Apple's approach to it makes good sense. Believe me, there is a reason that Apple positions an iBook portable system (and not an iMac) as the hub of your "digital lifestyle." Apple sees where the computing world is going and the company is trying desperately not to miss the boat...

"I predict that the original iMac will be remembered as the last tethered consumer desktop computer purchased aggressively by the public at large, created by Apple or any other company."

So, Roger Born's idea may well not be so outlandish after all. A new family of consumer Macs, sharing the same basic modular internal design, and muddying the distinction between desktop and laptop even further, could very well be what we will see on Monday. If not then, I'm confident we will see something like this in the not too distant future.

One concept that has been kicked around for to from time to time is a laptop with a detachable display allowing improved ergonomics for desktop use. If Apple could pull that one off, they would be hard-pressed to satisfy demand. It would be insanely great.

Charles W. Moore