What do you mean by fake? Most seem to be taking them as real. And some seem to have hard copies from retailers who sent them early - if they are fake I'm sure that there'd be discrepencies between these two types of early recievers.
I don't think when WotC put together the "Play 4e NOW" flash ads, this is what they had in mind.
This must be very disappointing for WotC, as if these pirated pdfs do have the color bars and crop marks on them, either they or their printer has a leak.