The update seems to have gotten lukewarm response overall and i can't blame consumers.
These things (CS3 & Quad Core MPs) are just that tad bit expensive. If i had the current/previous? 2.66 Dual Core machine, i wouldn't even bother.
With the exception of a DRASTIC change (like oh, say... switching to Intel), a new hardware release would likely never warrant replacing the previous generation outright. Often, not even then (my 1.5GHz PB is still chugging right along). It's not supposed to be a replacement for the previous generation. It is a step forward. Add together enough of those steps and an upgrade will be warranted. How many steps it takes will depend on the user and their application. So everyone maxing out their 1.25 Dual G5's might be good and ready to go after this beast. Anyone buying now will anticipate the hardware still being useful even after additional "updates" are released. Updates should not and cannot make the previous releases obsolete.
And once again... This option is not for consumers! They can be lukewarm as they like. Those who know they can use it are excited about this, and will be willing to pay.