I don't think the processors for the Xserves and Powermacs are the same as the power books, maybe the imacs are the same but they just got a speed boost.One thing we must remember in my opinion is that the 1.25Ghz and the 1.33Ghz processors did exist in desktops & Xserve before we found them in the laptops.
If they can put a 1.33 in the laptop - why not a 1.42 straight away? I think Steve wants to keep one possible G4 update in his pocket before the G5 is released in a notebook.