According to an unconfirmed source - next up for Apple is Xserve and Xserve RAID updates/introductions.
The Xserve was initially introduced in May 2002, and maintains the Dual 1GHz speeds. The Xserve raid was previewed at that time, but has yet to arrive. In November the Xserve RAID was delayed by Apple until early 2003.
According to the information provided, next in line is the Xserve - which is rumored to sport dual 1.4GHz processors, 166MHz bus, DDR333, and 250GB Drive Modules, and the long awaited Xserve RAID -- reportedly still with Fibre Channel, contrary to other rumors.
Though the source claims 1.4GHz speeds, it seems a 1.42GHz processor would be more likely much like the PowerMacs. As a new and unconfirmed source, it should be considered accordingly.