The 25th Macworld Conference & Expo in San Francisco kicks into gear this morning without an appearance by Apple Chief Executive Steve Jobs. Or maybe he will be there.

Though the Cupertino company announced last month that this will be the last Macworld Apple will participate in and that Jobs would not take the stage for his trademark keynote speech, the usual swirl of speculation about the event has filled the blogosphere. Some analysts think the Apple co-founder could show up for at least a cameo bow.

What is certain is that the tech world will be focused on the Moscone Center one last time.

Apple prognosticators don't expect new product lines to be announced at Macworld, given that Jobs isn't scheduled to be there to cast his marketing spell - company senior vice president Phil Schiller will take his place on the big stage. Also, the conference comes at a time the nation is mired in its worst recession in decades, not an opportune time to launch new gadgets.

Apple may be saving its next really big thing for later in the year. After all, the company is so closely watched that it can draw media hordes to its doorstep anytime it wants.

But even if there are no big announcements from Apple, there is apt to be news on Tuesday that will interest fans of the maker of iPods, iPhones and Macintosh computers.

"It's likely to be more evolutionary than revolutionary," said Michael Gartenberg, a vice president and research director for Jupiter Research.

Here are some of the things Apple watchers think the company will unveil:

n"‚A preview of its next-generation Macintosh operating system, Snow Leopard, which will eventually replace Leopard, which was released in the fall of 2007.

n"‚A redesign of the stripped-down Mac mini, which sells without a keyboard or monitor.

n"‚An upgrade of the all-in-one aluminum-cased iMac desktop computers.

n"‚A new version of Apple TV, which enables users to experience movies and digital music from their PCs and the Internet on TV screens and stereo systems.

n"‚An update of Time Capsule, the companion to Time Machine, Apple's backup software, to allow users to access personal content from anywhere on the Internet.

The wish list of many Macolytes includes an iPhone nano, a smaller and less expensive version of the popular cell phone that is also a pocket computer, some other touch-screen gadget and a tablet-like device. There's also been chatter about Apple jumping into the ultralight netbook market with its own easy-to-carry and less expensive laptop. None of these, however, are expected to make an appearance Tuesday.

"Frankly, we would be a little surprised if there is a major announcement," Shaw Wu, Kaufman Bros senior research analyst, wrote in a note to investors last week. "However, there is always the likelihood that Apple may surprise and send a message that Apple is a much broader and deeper company than one person, even if he/she is a living legend."

Analysts say dumping Macworld, which is run by an independent company, IDG World Expo, makes business sense for Apple. It will no longer be compelled to make major product announcements in January, the slowest time of the year for the company. Anticipation of new product launches had hurt important holiday sales of Apple products because consumers held back purchases until they saw what happened at Macworld. Rather than spend millions of dollars on the event, the company can use its retail stores to reach customers, as well as special media events.

"Why should Apple jump when Macworld says it should?" said Scott Rothbort, president of LakeView Asset Management, a longtime owner of Apple shares. "It will launch its products when it deems necessary."

Apple's withdrawal after this year leaves Macworld's future uncertain. IDG shut down its Macworld in Boston two years after Apple stopped participating in the East Coast conference in 2003. "It's not a great thing that Apple isn't attending (Macworld) in the future," said Paul Kent, vice president and general manager of Macworld.

With or without Apple, the next Macworld is scheduled for January 4, 2010, he added.

While Apple and Jobs give the conference star power, Macworld is much more than the famous keynote, Kent said. Much of the event is devoted to training, networking and shopping for products tied to the Apple ecosystem. As many as 500 vendors will set up booths on the show floor. An added feature to this year's show will be free classes, and one-on-one sessions, on using Apple products and software.

"It's a very big ecosystem," Kent said. "Our stock and trade is putting people together with products."

Contact John Boudreau at jboudreau@mercurynews.com or (408) 278-3496.

Infobox1
What: Macworld Conference & Expo
Where: Moscone Center, San Francisco
When: Runs through Friday
Cost: Ticket packages range from $150 to $1,895. Day passes to the show floor and special sessions are $45 and $49, respectively.
Web site: www.macworldexpo.com


Macworld attendance:
2009: 40,000 (estimated)
2008: 47,908
2007: 45,572
2006: 38,441
2005: 35,989
2004: 32,409
Source: IDG World Expo