Apple CEO Steve Jobs Tuesday introduced three cheaper, revamped iMacs just as the back-to-school selling season ramps up. The timing was important for another reason, too. The new models came just weeks after Apple's most recent earnings statement, which spelled out just how important Macs are to the company that dropped the word "computer" from its name in January.

In the year's second quarter, Apple sold US$2.53 billion worth of Macs, representing 47 percent of the its total revenue for the period. A year earlier, computers accounted for 43 percent of the company's sales in the same quarter.

"The iMac has been really successful for us, we'd like to make it even better," Jobs said near the start of his presentation (which you can watch on QuickTime video). "So how do we go about doing that?"

Exactly. How is Apple making its iconic desktop "better"? What follows is what could be gleaned from the 90-minute roll-out.

What exactly did Apple reveal? The company refreshed its iMac desktop line for the first time since September 2006 by dropping some prices and raising others, by upgrading the machines to faster processors, and by dumping models with 17-in. screens. Apple also tweaked the Mac Mini and, on the software side, released iLife '08, an update to the consumer media suite bundled with every new Mac, added a spreadsheet to the sold-separately iLife '08, and massaged the .Mac Web mail and storage service.

What didn't happen that the Net's Nostradamuses had predicted? Although the iMac refresh was tops on everyone's list, some had gone out on a limb -- or into left field -- and forecast the death of the Mac Mini (nope), a bump-up of the MacBook clan to the faster Santa Rosa chip set (no), and a firm date for Leopard's launch (not that either).

Let's talk money and iMacs; what happened to prices? Apple's reputation for holding the line on prices has taken a hit or two of late, and Tuesday's new lineup is a good example. The 20-in. model of Monday dropped $300, from $1,499 to $1,199 on Tuesday; and the 24-in. slipped $200, from $1,999 to $1,799. The catch -- there's always a catch -- is that the entry fee to iMacLand jumped $200, from $999 for the now-gone 17-in. to $1,199 for the cheapest member of the family.

No one should be shocked. Last September, Apple cut the price of the lowest-priced 17-in. model by $200 from its January introductory price of $1,199 and dropped the 20-in. model by the same amount.

But Jobs made it clear Tuesday that Apple won't ever practice pricing slash-and-burn, at least while he's on watch. When a reporter asked if Apple's goal was to crack the PC's market-share lock, Jobs' answer was telling. "We can't do it, we can't ship junk," he said. "There are thresholds we can't cross because of who we are."

Jobs trumpeted the new design and the new look of the iMacs. Sizzle or steak? "Aluminum and glass" was a phrase he used several times to tie the new iMacs with the MacBook Pro line, design-wise. By Apple's own spec sheets, the systems are not any thinner, but they are slightly smaller on the horizontal and vertical. The 20-in. model is 2 pounds lighter, while the 24-in. machine tips the scales at 0.7 pounds heavier.

The LCDs are glossy-coated, something that Jobs bragged about, saying that polled consumers had overwhelmingly preferred the look. The MacBook Pro and MacBook notebooks let buyers pick between glossy and nonglossy; no such choice for iMac customers.

One expected change, however, didn't happen. Sources had told some bloggers and Apple-only news sites to expect the elimination of the iMac's distinctive "chin," the area of the machine's face below the display. The new models still sport the chin, but it's slightly smaller thanks to the 1/10th of an inch shrink between the new and old models' overall height measurements. The chin also looks smaller, thanks to the black border now surrounding the iMac's built-in LCD.

Actually, it's the keyboard that looks the most different from its predecessor. Not only is it wafer-thin compared to the old version -- it's just a bit over one-third as tall at the front, for instance -- but it boasts a brushed metallic look (rather than the previous plastic), several new function keys (that call up, for example, Exposé and Dashboard) and flat, square typing keys.

What's the weakest link of the new iMacs? Even though Apple anted up the video cards to the ATI Radeon HD 2400 XT and HD 2600 Pro (the former only in the $1,199 20-in. model), the graphics subsystem is a stumbling block for gamers, especially for those using Boot Camp to run Windows and its much deeper game library, on an iMac. Tom's Hardware, for example, puts the new iMac's graphics cards way down the list on game frame-rate benchmarks.

What's one significant change that Jobs didn't mention? The top-of-the-line configuration, a 24-in. unit for $2,299, comes standard with an Intel Core 2 Extreme processor running at 2.8 GHz. That chip, so new it's not even discussed on Intel Corp.'s own Web site, debuts on Apple's platform.

The processor, labeled the X7900 by Intel, is a sibling to the X7800, a 2.6-GHz CPU designed for mobile computers that Intel touted it in a July 16 launch as "the world's fastest-performing mobile processor."

Unlike rivals such as Dell Inc. and Hewlett-Packard Co., Apple uses chips normally slated for notebooks in the iMac, reflecting their laptop-like design. The higher temperatures of traditional desktop CPUs would give the iMac thermal problems, or require larger, and louder, fans.

What's the new biggest rip-off? Check out the configuration tool at Apple's online store; The Gang from Cupertino want you to pony up $850 to bump the standard 1GB of memory in, say, a 20-in. iMac, to the full complement of 4GB. $850... yes, you read that right. Dell, not known for knock-down RAM prices, charges buyers of its Inspiron 530 desktop less than half as much -- just $370 -- for the same bump.

Shopping in the after-market can save a ton. We found compatible Kingston-branded 2GB modules for $141 each at Buy.com, making a 4GB upgrade $242.

Difference? $608, or a bit more than what you'd pay to add a second, 20-inch Apple Cinema monitor to the desk.

Everyone was saying the Mac Mini would be axed. What happened? The scuttlebutt wasn't surprising -- the Mini has languished with the slower Intel Core Duo for more than 16 months -- but the news of its demise was greatly exaggerated. For now, anyway.

Instead, Apple held the prices of the Minis at $599 and $799 but bumped up the processors in the two models to 1.83-GHz and 2.0-GHz Core 2 Duos, respectively (from 1.66-GHz and 1.83-GHz Core Duos), increased the standard RAM to 1GB from 512MB, and replaced the 60GB and 80GB drives with 80GB and 120GB disks.