TheMadScientist i hear what you are saying but surely the point is that sites that were doing just fine have suddenly dropped all of their traffic? Was personalised search switched on the same time as the update? In my mind the issue is one or more of the following :-
new design change-i can't see this impacting to this degree?
algo update-not completed yet?
The fact that the feedback for shopping sites is being misreported tells me all is not well at Google right now.
The fact remains that a site that used to take 4 figure sums is now doing zero.
Until we have something official from Google we can't really look at changing our sites?
I seem to remember a certain Mr Cutts saying webmasters do not need to worry about this update, well, a complete lack of revenue is slightly worrying to me!