PSP-4000 is actually a typo

It seems that all the brouhaha concerning the PSP-4000 boils down to a typo error, where the ad which featured Little Big Planet PSP accessories did list down the PSP-4000 as a compatible device, but it is actually non-existent. According to the ad company, it was a mistake on their part and they do not have any knowledge of Sony releasing a new device. Do you think they’re pulling a fast one with a conspiracy at hand, or is it a real honest mistake?