Also most of people can tell the picture from a P &S from a APS_C, let alone FF.We should not assume that they are that naive. Also Canon can always educate people in their advertisement and literatures.
I beg to differ. IMHO, people that have owned both FF and crop sensor bodies can easily spot the difference in image quality between the two. However, there are at least a half-dozen posts made here daily that claim their 7D or xxD body produces images on par with a FF body. They even post the indisputable evidence (links to some yahoo's blog "testing" FF and crop sensor bodies back-to-back by taking photos of bookshelves and their girlfriend's hairy arm pits) to back up their claims
When I'm on assignment, people are shocked to find out that I keep a lowly 12.8 mp 5DC as a backup body. They're stunned that a working pro has a body with fewer megapixels than their Rebel or 7D. You're kidding yourself if these kind of consumers have any idea of the different sensor sizes manufacturers offer. They just put their cameras in full Auto mode, and fire away.
If you can't distinguish the difference in image quality between a 1.6:1 and full-frame body, why spend the premium for a FF body? It's the same reason why I talk people out of buying DSLRs and suggest that they stick with point-and-shoots, on countless occasions. If this rumored entry-level, "lower mp" camera is real, that's the question Canon's marketing department is going to have to answer.