In creating the following two articles and responding to many emails, I also did a bit of research into what I've written in the past and did some rethinking about where Nikon is today and their likely path forward.
Back when we were two years into the D700 and the first thoughts of possible replacement started forming (partly because of the D3s/D3x launches), my initial thoughts were that Nikon should do a D700s and D700x update. The logic in this is simple: the echo of sensor use makes a lot of sense. Let the pro mix and match as they need. The problem for Nikon with that logic was simple: money. The D700 was US$3000, the D3s was US$5100 and the D3x was US$8000. If you exactly matched sensors at the lower price point, you would tend to drive people to the lower price point. Put a different way: Nikon simply didn't put enough differentiation in the small and big bodies, especially when they offered a grip for the small body (more on when that happened in a bit).
As it turned out, the D3x at US$8000 has been replaced by a camera at US$3000 anyway. But not until Nikon extracted as many of the higher prices from us as they could. Now Nikon has multiple problems in the high end lineup: the best body is only made in the lowest megapixel count, the highest performance in terms of focus/frame rate is only available in the lowest megapixel count body at the highest price, the highest megapixel count is available in the least expensive pro body, plus there's a consumer body at a lower price that somehow manages to wedge in between everything.
A relatively simple solution exists to Nikon's dilemma, and it would make those remaining "where's my D700 update" folk happy: completely rationalize the pro lineup the way Nikon started out to.
Wayback Machine, please. Cranking it back to 2001. Press the button, watch the puff of smoke, and...we're at a Nikon press conference outlining how they believed that there were two primary types of pros: performance-oriented, and studio-oriented. The performance group included sports and photo journalists (conspicuously absent was mention of wildlife photographers, a constant blind spot in Nikon's marketscope). They wanted high frame rates and high ISO quality. The studio group also spilled over into landscape photographers who shared the same high-resolution, slower work style. Nikon's answer was two cameras, one for each group: introducing the D1h and D1x.
As we fast forward back to today we see the D2h and D2x, the D2hs and D2xs, the D3 and the D3x (and look at the smaller splinter, the D300!). Today we have... Wait, what? The D4 and D800? That's not right, is it? Something's really strange about this new pairing.
That the D800 is essentially the D700 replacement is also strange. A smaller performance body has suddenly become mostly a smaller studio body, which is what has provoked a lot of the protests about the D800's specs. Nikon established the performance/studio coupling, then broke it.
Of course, the D800 has one aspect of the performance: high ISO work is perfectly fine, as I've pointed out. The only "broken" thing in the D700 to D800 progression as a performance camera is frame rate, which Nikon only partly addressed with the DX crop.
So what's the relatively simple solution? Well, exactly what I asked for in the first place back in 2009: a D800h and a D800x. Wait just a second, we already have the D800x. It's called a D800E. Hmm. So if Nikon would take a lower megapixel sensor and drop it into the same body with a higher frame rate, we'd have a D800h. The more I think about this, the more I'm back to my original position: Nikon would be silly not to do this. It solves so many of their problems and keeps their marketing message the same as it has been for twelve years for professionals: pick performance or pixels.
The problem is actually the D4 and the very likely upcoming D4x. What Nikon hasn't done with the D300/D700/D800 bodies is put quite enough distance between the features of the small pro bodies at a lower price and the big pro bodies at a higher price. The camera that they actually screwed this up with wasn't the D300 (it had a DX sensor, and that alone is enough differentiation, I believe; the D3/D300 coupling was very, very logical and well thought out). It was the D700 that messed Nikon up.
Please note that I didn't write that the D700 was a bad camera. It was great. Still is. No, it's when Nikon put an FX sensor into that smaller pro body, they didn't really have enough differentiation between the small body pro performance camera and the high. Nikon partially solved that by squeezing another stop out of the D3 and not putting that sensor into a D700s. You see the trap they're falling into here? Yep, they differentiated the D700 and D3s by sensor. Yet for a pro, it's the sensor that is the center of their upgrade needs. With the D4 and D800 they're doing it again: diffrentiating by sensor, but in a wierd way. They've trapped themselves in a tough place.
So I'm back to where I was in 2009. Nikon needs a D800h and D800x, plus a D4h and D4x. This then leads to one of two further conclusions: (1) if the D800h and D4h are the same sensor and frame rate while the D800x and D4x also share a sensor and frame rate, then the D800 and D4 bodies need more differentiation to justify the US$2000+ price difference. You can see Nikon experimenting a bit with that with the Ethernet, WT-5, and a few other aspects of the D4, but it's not enough to justify the extra cost. (2) the D800h could be 16mp while the D4h is 24mp, and the D800x could be 36mp while the D4x might be 48mp+. But this forces the pro to make sensor choices that determine body choice. At the moment, Nikon is caught in a trap of their own making, and #1 is where they goofed up: not enough body differentiation.
As a working pro, frankly I'd buy all four bodies I just described under either scenario. Well, okay, I'd want to buy all four. Economics might force me to pick a subset of two, but in either of those scenarios, any subset of two is justifiable to someone.
So while I've argued against many of the "where's my D700 upgrade" folk strongly in my articles (and stick by what I wrote), I can also see a rationalized pro lineup that would solve their problem without hurting anyone. Indeed, a D800h/D800x plus D4h/D4x lineup would be intensely strong, and pretty much protect Nikon from any incursion into "pro" the Sonys and others of the camera world want to attempt. Heck, it would be more rationalized than Canon's lineup, too.
I know what a lot of you are thinking: when can we get this? Yeah, me too.