Without the star power of legendary Apple chief executive Steve Jobs, Macworld this week is expected to be less exciting than in the past, with Apple most likely to announce product updates as opposed to something brand new.

Of course, no one knows for sure what the storied company has planned, given that Apple has a policy of never discussing upcoming products. Nevertheless, analysts and the blogosphere have been busy for several weeks offering their predictions.

Customarily, Jobs has kicked off the show with new products to send fans, and often the tech industry, into a tizzy. His absence this year, complicated by a hormone imbalance, has convinced many analysts that Apple is unlikely to unveil a new product, since the company would want to use Jobs' ability to excite the Apple faithful for such an event.

Instead, this year's keynote speaker, Phil Schiller, senior VP for worldwide product marketing at Apple, is expected to launch updates to the MacBook line, the Mac Mini, and Apple TV.

"I absolutely agree that there won't be any major product announcements," Van Baker, analyst for Gartner, told InformationWeek. "It's going to be a refresh of current products and nothing earth-shattering." Baker declined to speculate on which products would be updated.

But other analysts say Apple is likely to give a sneak peek at Snow Leopard, the next-generation of the Macintosh operating system. Officially called Mac OS X 10.6, the software will be optimized for multicore processors and designed to facilitate future Mac platform innovation. The OS, a preview of which was released last June, is expected to ship this year.

On the hardware side, a refresh of the 17-inch MacBook Pro would be welcome news for fans. The largest of the professional line was left out of Apple's notebook event in October, when the company launched updates of the 15-inch and 13.3-inch MacBooks.

Fueling the speculation is Intel's release Dec. 28 of its lowest-priced quad-core chip for notebooks. The Q9000 sells for $348, which is about a third the price of its highest-end quad-core processor and less than half of what Intel charges for the mainstream products. The latest chip would make it possible for Apple to continue selling the 17-inch MacBook Pro at less than $3,000, which is important in the current belt-tightening economic downturn. The MacBook Pro currently sells for $2,799.

Other hardware updates could include a refresh of the all-in-one, aluminum-cased iMac desktop and a redesign of the Mac Mini, a stripped-down computer that comes without a keyboard and monitor. Starting at $599, the Mac Mini, the least expensive Apple computer, has received little attention from the company since the last release in summer 2007.

Apple also is expected to unveil a new version of Apple TV, a device that lets people experience movies and music from PCs and the Internet on a digital TV. Apple could also update Time Capsule, the companion to Apple's backup software. The device, which is also a Wi-Fi base station for the home, allows users to back up multiple Macs. Following this year's Macworld, the event is unlikely to ever be the same. Along with Jobs' absence, Apple announced this year that it would no longer participate in Macworld, which is run by an independent company, IDG World Expo.

Apple's decision makes business sense, analysts say. Rather than spend a lot of money on the trade show, the company can reach customers directly through its retail stores and can put on its own special events.

Baker said Apple isn't the only tech vendor moving away from trade shows as a way to reach customers. "Trade shows in general are on the decline," he said, noting that many of the shows he attended this year, even before the economic slowdown took hold, were smaller than in previous years.

Companies are finding less expensive ways to get their message out through the Web and their own special events, Baker said. "Trade shows in general are starting to use some of the clout in the market."

Apple's absence, however, has brought even more uncertainty to the future of the San Francisco conference, which is expected to attract 40,000 people this year. When Apple pulled out of Macworld Boston in 2003, the show closed two years later.

IDG believes the San Francisco event can continue without Apple, given that it remains a showcase for developers and third-party vendors who are part of the Apple ecosystem. Besides offering a product showroom, Macworld also has training sessions for developers and is a major networking event.

IDG on Dec. 30 said it would hold a "town hall meeting" at Macworld for attendees who want to provide input on how future events should be organized.

Meanwhile, Jobs' absence has sparked fear among the Mac faithful that he could be gravely ill. Jobs battled pancreatic cancer four years ago and has said he is cancer free. However, answers about his health were revealed Monday when Jobs wrote a letter saying he was recovering from a hormone imbalance. Apple's board issued a statement within minutes confirming that Jobs would remain on as CEO until the charismatic leader decides to step down.

Macworld continues this week until Friday.