I'm gonna reiterate some of what I just posted in a different thread.
Canon is likely quite happy with the performance of the 5D3; it's selling like crack, it actually does do a lot of things considerably better than the 5D2, at least for most of the crowd who asked for those improvements.
I sure hope they are listening to all the forum griping tho, as well as those of us who've also bothered to let them know directly, that we expected better overall sensor performance from them, especially at the low ISO end.
I really think Canon needs to look at what the competition has brought to the market and pay attention to its loyal customers who'd like some of the same without having to buy it from the competition.
There's one way to help them do that.... TELL THEM.
Because right now, the following competition products have an edge in low ISO IQ.
Nikon D800, D4, D7000, D5100 and Pentax K5.
The freshly announced Nikon D3200 is also gonna make some waves with its 24MP crop-sensor. If it can retain the clean shadows the other bodies listed can provide, plus the simple market appeal of all those pixels at a very competitive price, it's going to steer some attention away from Canon.
Ricoh-Pentax is also about to start a renewed marketing campaign as well. They have some great products that are a bit different in some ways, very creative. I've been thinking of playing with some of them myself. (That little Q is just so cute.. and capable.)
This has been a one-horse race for a while but Canon's jockey is about to start feeling some hot breathe from the competition closing in on his backside.
Even Harley Davidson eventually had to start building better bikes in the face of the competition.