You realize your last three points, DR, Low ISO Noise, and Shadow Recovery....are really all the same thing, right? Dynamic Range IS effectively a measure of noise,
No, DR is not a measure of noise. You could have 3 stops of DR and lots of noise. Similarly you could have 3 stops of DR and no noise. They are not combined.
Your thinking photon shot noise. I mean read noise. Dynamic range is the ratio from the brightest highlight (the clipping point) and the read noise floor (that may be the RMS, the maximum, the square root, depends on the exact method of determining DR). However you calculate it, dynamic range is specifically limited by read noise.
Shadow recovery is simply a benefit of low ISO read noise. So, in your little table, there are really three points total: Live View, Silent Shooting, and Dynamic Range. The 5D III wins hands down on two points. The D800 wins hands down on one. If you throw in High ISO dynamic range (or High ISO SNR), then the 5D III wins on another point.
Or to rephrase this, Canon wins on using the camera but the Nikon wins on producing quality images. Personally, I don't even know why "Silent Shooting" makes it to the list.
Silent Shooting makes the list because a huge number of customers asked for a quieter shutter. Canon gave their customers what they asked for. Same deal with the AF system...Canon gave a very vocal and very large user base exactly what they wanted: a better AF system. Again, same deal with fewer megapixels and better high ISO. That was probably the biggest thing Canon customers asked for, including myself and pretty much everyone I know.
When it comes to listening to their customers, Canon wins every time in every way. Can't really get better than that, and given their track record, it shouldn't be long before Canon gives their customers something with better DR as well. The only reason they haven't is because the DR game only really changed with the D800, and that was released about the same time as the 5D III. Now people are asking for it, and I have no doubt Canon will deliver.
A two-shot HDR blend will also take care of any DR problems you have quite nicely (if you push it to the extremes, a two-shot HDR blend could be separated by 10 stops (+5 and -5), allowing ~16-18 stops of DR in the final 32-bit HDR image...more than enough.) HDR blending is a simple ordeal these days as well. Is it less convenient? Sure, by a very small amount.
Sure, but you can do the exact same HDR tricks with the D800 and to even greater effect than with Canon.
You would only have about two extra stops of DR with the D800, regardless of whether your talking about a single-shot context or HDR context. We already knew the D800 had two extra stops of DR, though.
Enough to warrant spending thousands, maybe tens of thousands, switching brands just to have the D800?
Probably not. Canon will figure out their sensor stuff soon enough, and they'll be back in the game.
What if Canon can't/don't figure it out?
Hypothetically speaking...nothing changes. People are still buying Canon cameras in huge volumes. Canon's worldwide market share wavers up and down a few percent every few years. I don't foresee that changing. DR is not the only thing that matters, certainly doesn't seem to be impacting Canon's sales to any meaningful degree. So, those who want more DR will move off to Nikon, or add Nikon to their kits, and keep using both brands.
Either way, assuming Canon is literally incapable of competing on the DR front, I don't really foresee any major change, not unless someone comes out with a 16-bit ADC with 15 stops or more of DR. If that happens, then I think the game would change. Hypothetically speaking, of course.
How long has it been since the 5D Mark II came out now?
And in all that time, we haven't seen any evidence of a sensor that is any better - or rather Nikon have made great advances with their sensors, Canon haven't moved...
Why is it that you Nikon radical fanboys refuse to see the areas where Canon sensors HAVE improved? Canon sensors HAVE improved! Canon sensors currently have the best noise performance I've ever seen at high ISO. They also support the fastest readout rates of any DSLR sensor on the market at the current time (14fps @ ~19mp, or approximately a 500MB/second throughput rate). I've seen clean, entirely usable ISO 51200 sports shots with the 1D X. I've seen usable ISO 12800 shots from several generations of Nikon cameras, but nothing at ISO 51200 from a Nikon that looked truly usable or anywhere nearly as clean as a 1D X shot...too much color noise, too much loss of detail (probably because every setting above ISO 12800 is a "fake" expanded setting, which is really just the same as ISO 12800 with a post-process digital exposure lift....we've been able to do that with software for years.)
It is not 100% about low ISO DR. The greater majority of photographers who use DSLR cameras, which includes sports, aviation, wildlife, bird, event, wedding and street photographers as well as photojournalists, tend to shoot at higher ISO settings. Much beyond ISO 400, DR is limited by physics. Even significant improvements in Q.E. result in marginal improvements in DR, if any. The only thing that really matters at high ISO is SNR.
In this respect, Canon owns the market. It's WHY they own the market. Canon cameras offer the best tools that support the greatest majority of photographers for the widest variety of photographic goals and styles. Canon sensors have most definitely improved in the last four years. The 5D II sensor wouldn't stand a chance against any one of the sensors from the 1D X, 5D III, 6D, hell even the SD1 seems to have a damn good sensor. DR isn't the only thing that matters, and while it may be the most important factor to some photographers, it is really the least important factor to most photographers.