As is its custom, Apple is keeping schtum about its product announcements for the Macworld Conference and Expo, which opens today.

Some Apple enthusiasts are predicting the unveiling of faster machines. However, weak conditions in the PC market could spoil those hopes, according to Roger Kay, a PC analyst with research company IDC.

"The word on the street is that Apple didn't do that well during the holidays so they have inventory lying around," Kay said.

A backlog of unsold notebooks and flat-panel iMac desktop computers could mean that plans for new PC products will be delayed. Releasing a new product "would distract them from existing markets," Kay predicted. "They need to clear the inventory."

Moreover, UBS Warburg analyst Don Young issued research in early December that said Apple would not be among the PC makers to see growth in desktop shipments during 2003. Although the overall market is expected to expand by seven per cent, he said Apple would miss out on that trend with a three per cent dip.

During 2002, Apple shipped roughly 3.1 million computers globally, nearly equal to the number of machines sold the prior year, but almost 1.5 million less than 2000, according to a December filing with the Securities and Exchange Commission.

One hardware upgrade that some Apple watchers have hoped for is a flat-panel iMac with a larger display. The first of Apple's distinctive flat-panel iMacs was released a year ago with a 15-inch display and was followed by a 17-inch model. The declining cost of some computer components could make it feasible to upgrade the display, according to one analyst.

IDC research analyst Jennifer Gallo said: "With regard to flat-panels, pricing has been going down. Over the holidays, flat-panels were going down in price aggressively. You'll see that more going forward."

The week leading up to Macworld has brought a flurry of predictions about new applications from Apple or updates to existing programs. Some of those forecasts have already come true.

On Thursday, Apple released the first complete version of its iSync software, which synchronizes contact and calendar information between Macs and Palm OS devices, Apple's iPod digital-music player and Bluetooth-enabled mobile phones. It also made available an update to iCal, its calendaring software.

Giga Information Group research fellow Rob Enderle said on Friday that Jobs might use his keynote to introduce a version of Apple's popular iPod digital music player that can play videos.

One device that does this, called the Multimedia Jukebox, is already on the market, developed by Archos. In addition, digital-media device maker SonicBlue is planning to release a portable digital music and video player, Enderle said. Upgrading the iPod to compete against those devices would be a logical step, he said.

"It's got the capacity, it's got the battery life. It would probably just need some increased processing power," Enderle said.

The only thing that Apple watchers can be sure of is that Apple CEO Steve Jobs will wear his trademark black turtleneck and faded jeans when he delivers his keynote address on Tuesday.