So Canon did all of this yet there are stories already about a quick replacement of the 5D3? Well, that tells you how important that list of "improvements" that you listed is, doesn't it?
It tells me nothing. There have been 'stories' of a new 100-400L for what...7-8 years? There have even been at least two patents. Where's the lens? Stories.
As for a 5DIII 'replacement', I'd say BS and wishful thinking. Many of the people clamoring for a high MP camera from Canon don't want to pay the price for a 1-series body, and from such dreams, rumors are born.
Don't be so fixed on megapixels as being the only problem that needs attention.
What needs addressing is IQ. A combination of more megapixels and improvements in noise, DR, etc, is what is sought.
In essence, this is what the entire Canon community (apart from a few deniers such as yourself) seem to be saying - a new camera that costs $800-$900 more but my pictures are pretty much the same as before. WTF?
No, what the Canon community here on CR (and, I would argue, the photographic community at large given how many 5D III's have sold) is saying is that IQ is not solely the domain of the image sensor. There are other aspects of IQ as well. The AF system is indeed a very significant factor that assists photographers in maximizing IQ. The increase in frame rate is another significant factor in maximizing IQ. The best sensor in the world doesn't matter a wit if its AF system and frame rate are low enough such that you can't actually capture the one frame where everything is still and sharp...a soft frame is a soft frame, regardless of whether the sensor pumps out beautifully soft pixels or not.
Sure, read noise is an issue in the sense that it limits DR, however that is only an issue at the lowest few ISO settings. Compared to cameras two generations ago, which frequently topped out at 6-9 stops of DR, Canon cameras offering 11-12 stops is still quite good. Hell, even the top of the line medium format cameras still offer less than 12 stops of DR. Having 13-14 stops of DR is still rather new, and requires the absolute latest and greatest 180nm technology to achieve, and only matters at the very lowest ISO settings.
I'd offer that there are far more photographers who shoot high action in one form or another who use ISO settings 800 and above than photographers who shoot still scenes or low action and use ISO settings 400 and below. To the greater majority of photographers, the AF system and frame rate are critical factors to attaining the IQ they require. To that end, I'd say Canon did well by their customers
, and clearly listened to what their customers were asking for...less megapixels, higher ISO, less noise at higher ISO (hell, even I asked for that!!!
Let me put this another way. If I pick up and use a 5D Mark III, what am I going to notice as being significantly better aside from the AF? Nothing. What do I see as being better when I look at the images on my computer? Nothing.
So $800 or $900 more for improved AF.
Sorry, I completely disagree with that conclusion. With a few notable (and *cough* vociferous) minority exceptions, the consensus was that the sensor-based IQ of the 5DII was excellent - it wasn't broke, and Canon didn't fix it. Because of that excellent IQ, many people used the 5DII for tasks for which it's not ideal. There's a reason I and a whole bunch of other people had both a 5DII and a 7D. What Canon did with the 5DIII was, IMO, huge. They took a camera with already excellent IQ, and improved substantially on the overall performance.
For 5DII tripod-only, ISO 100 shooters, I can see the incremental nature of the upgrade. But if that's you, the answer is simple - keep your 5DII.
You state, "If I pick up and use a 5D Mark III...," which I take to mean you haven't.
After a couple years shooting a 7D and a 5DII, when I tried out a 5DIII what I immediately noticed was that it felt 'fast'. For example, the difference between the ~200 ms shutter lag of the 5DII and the ~100 ms lag of the 5DIII is very apparent.
From the ones I've picked up in stores, I've not noticed any difference. If I pick up a stop watch and time 1/10th of a second vs 1/20th of a second, it is almost impossible to do manually because the resolution of my finger pressing ability is not that fine.
Perhaps your finger-pressing ability is not that fine, however our minds can indeed sense minute differences. Our ability to measure time perceptually is not limited to 1-second increments, and even if we cannot send an impulse from our brains to our fingers in 1/20th of a second, that does not mean we cannot sense the difference between 1/10th and 1/20th of a second. Especially in the context of a camera shutter...looking through the viewfinder, it is very easy to recognize a TWO-FOLD difference in shutter performance, especially when holding the shutter button down and watching frame after frame race past at nearly double the speed. I'll say that again...a TWO FOLD, FACTOR OF TWO, 100% or DOUBLE the difference in shutter speed...relatively speaking, that is a huge difference!
My overall impression of the 5DIII is that using it feels like using a 7D from a performance standpoint, and it delivers the IQ of the 5DII - that's a powerful combination, and whereas the 5DII was liked (almost exclusively) for its IQ, the 5DIII is, IMO, the best all-around dSLR on the market.
Except that for the price the IQ is very very ordinary.
What exactly is "ordinary IQ"? I think your generalizing a bit too much...