This eWeek article details some changes in Motorola's road map for it's PPC processors:
However, the new road map does highlight some revised aspects to the G5 family. New features include the adoption of the RapidIO Interconnect Architecture and symmetric multiprocessing capabilities (first seen in the PowerPC family with the G4 processor). Other revisions are initial speed estimates of 800 MHz to 2+ GHz (as opposed to past estimates of 2+ GHz to start) and a 0.13 micron manufacturing process instead of a 0.10-micron process.
also discussed is some possible hedging of the processor names by Motorola:
Overall, Glaskowsky said, this information was "consistent" with reports he had been hearing of Apple announcing G5-based computers at next month's Macworld Expo. Even if, he said, other reports, about Macs badged "G5" but sporting a PowerPC 7460 chip -- previously considered part of Motorola's G4 generation -- pan out. The PowerPC 7460, carrying the code name Apollo, has not yet shipped in any Mac model.