Despite the rumors of an iPhone "nano" and a tablet sized iPod touch, Apple is more likely to use the Macworld expo to announce updated versions of several existing products, according to a variety of sources. Analysts' forecasts have focused on a new line of iMacs and a refreshed 17-inch MacBook Pro utilizing aluminum unibody construction. The company could also be prepared to launch a new Mac mini and Apple TV, along with the latest versions of Time Capsule and iWork.

Several predictions for new iMacs suggest the approaching release of a 28-inch model, a set of 24-inch devices, and two 20-inch variants. The company could be transitioning to NVIDIA-based integrated graphics with the 20-inch refreshes, while the 28-inch iMac is said to feature an Intel i7 Core processor.

A new 17-inch MacBook Pro is claimed to feature an aluminum housing, similar to the MacBooks announced in October, although the design allegedly switches to a fixed-in-place battery. Although the potential change will be viewed as inconvenient, the adjustment could indicate the inclusion of a higher-capacity battery.

Sources indicate that an updated Mac mini should include dual display connectors, an additional USB port and a FireWire 800 connection. The device is also likely to include a NVIDIA-based chipset.

Times Online also points to a revamped Apple TV, in addition to several software updates including Time Capsule and iWork. The report claims that the company has embraced cloud-computing architecture for its suite of programs for word processing, presentations and spreadsheets, which will be offered as web-based applications.

The exact details of Apple's Macworld announcements will remain unknown until the keynote address. The company has made a concerted effort to conceal its banners with black and white cloth.