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.
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. 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.