The $900 Acer Aspire S3 ponies itself up as a cheaper MacBook Air alternative. Photo: Jim Merithew/Wired

The computing industry calls them ultrabooks: super-thin, super-light, high-performance notebooks. Apple’s wafer-thin MacBook Air partly inspired this new category, and a lot of these devices are doppelgangers for that highly successful notebook.

In 2011, Windows-based ultrabooks haven’t been flying off shelves. In fact, Acer and Asus have reportedly cut back their manufacturing orders by 40 percent. Nonetheless, Intel is pushing ultrabooks as a key notebook strategy in 2012. The Consumer Electronics Association expects to see 30 to 50 new ultrabooks launched at CES 2012 in January, and iSuppli projects a “massive level of growth” in the space.

Intel CEO Paul Otellini even wants manufacturers to incorporate a touchscreen into next year’s models in support of Windows 8. Will a flood of new models and features supercharge sales? Analysts say that if they’re done right, ultrabooks could be the next big thing.

“Interest has been high. People are asking about them — are they suitable for the corporate environment? It’s a very promising category,” says Forrester analyst David Johnson, noting that while PC ultrabook sales have thus far been “modest,” the category as a whole hasn’t been around that long.

Ultrabook is actually a term that Intel cooked up to differentiate high-performance, ultraportable notebook offerings from mainstream notebooks and the tablet market. It’s a catchy moniker, but makes the true definition of ultrabook something of a moving target.

The industry generally agrees that an ultrabook should satisfy three key consumer demands: instant-on operating system boot-up, good battery life, and extreme portability.

PCWorld classifies ultraportable laptops as having a screen size under 14 inches (11 and 13 inches are common ultrabook sizes) and weighing less than four pounds. But in addition to these parameters, the industry generally agrees that an ultrabook should satisfy three key consumer demands: instant-on operating system boot-up, good battery life, and extreme portability. Until the iPad burst upon the scene and delivered these features in a device, PC notebooks hadn’t really addressed that niche.

The challenge for ultraportable notebook makers is to deliver this trio of of convenience features without sacrificing raw processing performance, which consumers also expect in a general-purpose notebook PC. Apple has managed to do this in its MacBook Air, and now the onus is on PC manufacturers to deliver as well — at the budget-friendly, sub-$1,000 price points that PCs are known for.

This isn’t easy to do, especially when the instant-on feature requires hosting a tablet’s OS in an expensive solid-state storage drive, or SSD. Tablets can get away with relatively small SSDs in the 16GB to 64GB range, in large part because the Android and iOS operating systems have relatively small footprints. But to comfortably load and operate MacOS in the MacBook Air, as well as fulfill all other notebook storage functions, Apple needs an SSD at least 64GB in size, and even offers Airs with 128GB and 256GB SSDs, even pricier propositions.

Remember: Ultrabook SSDs accommodate not only the OS, but also all the applications and document files a user might install, create, import and download. The upshot: Tablets have taught everyone the convenience of instant-on device boot-up, but integrating this feature into full-fledged notebooks is a more expensive proposition.

“The tablet market woke up the PC industry on a number of fronts,” Display Search analyst Richard Shim says. Indeed, although the MacBook Air debuted in 2008, it was seriously slimmed down in 2010, and, in recent iterations, its core specs received a serious boost too (the 2011 MacBook Air outperforms every 2010 MacBook Pro in performance benchmarks).

Currently available PC ultrabooks include the Acer Aspire and Toshiba Portege Z835, both priced at $900. The Asus Zenbook is another option, which starts at the same price point as the MacBook Air, $1,000.

A number of ultrabook models offer stellar internal components. “You see full, excellent specifications, like i5 and i7 processors or other high-performance chips, as well as SSD storage, which is becoming the hallmark of the ultrabook class,” Forrester’s Johnson says.

With super slender frames — often in the 11-mm to 18-mm range — ultrabooks tend to abandon otherwise standard features like Ethernet and monitor ports, which are always present in larger notebooks. But that super-thin look is an essential part of the ultrabook aesthetic.

“Manufacturers are trying to make the ultrabook more distinct, while also trying to enhance usability,” Shim says.

Enter Intel’s Paul Otellini, and his desire to see touchscreen integration in Windows 8 ultrabooks.

PC makers tried the touchscreen thing a few years back, and failed miserably. At the time, many required a stylus, and traditional point-and-click applications weren’t convenient with touchscreens. “Imagine having to use a stylus to try to tap and edit a tiny cell in Microsoft Excel,” Johnson says.

But sometime in late 2012, Windows 8 should provide a touch-friendly PC interface that doesn’t require a stylus. To this end, Microsoft has promised to redesign a number of services in its mobile-friendly “Metro” user interface.

Of course, adding touchscreens should only increase ultrabook manufacturing costs, but Otellini seems hopeful that Intel and its partners can drive down the costs of touch technology.

“To hit the volume price points, we need to span $699 and up, and that’s the goal for next year,” Otellini said at an Intel conference on Tuesday. That’s right — he wants those $1,000 ultrabooks to be in the $700 and $800 range, with a touchscreen added. Starting next year.

Shim isn’t quite so hopeful. “We don’t see [touchscreen ultrabooks] happening for another couple of years,” he says. But with “more and more devices utilizing touch,” it’s definitely the direction the market is headed, he adds.