And now we've come full circle, back to my original post. Alex may not be quite serious, but it is somewhat true. The 5D2 seems to be exactly what I want. High pixel count, high ISO performance, HD video, and all for a reasonable price. And I look at Nikon's lineup, and im thinking...ok..where is this going to fit. I do hope the D700x will have all this, because the D3 line sure isnt offering this.
My story above is not actually a true story. It's just an example of what I have experienced many times. Maybe ISO1600 is a bit much, it usually is more like ISO800, but even at 800 i find my D2x images rarely acceptable.
I think you'd find the 5D-2's AF a bit of a disapointment for macro and fish photography coming from a Nikon (or for that matter a pro-series Canon), but for wide angle its hard to fault (except for no 10-17mm, which curses all full framers).
From my point of view, the vidiot function they can keep. But I accept others think its great. For me high quality UW imaging has always been about optimisation of all your kit, not jack of all trades. At the Antibes Festival I saw Danny Van Belle's Lembeh film and was blown away. Something like that isn't produced with half your mind and kit thinking about stills.
I'd also say D2X images become unacceptable at ISO 400. While D300 become unacceptable at ISO 1600 and D3/D700 above ISO 3200.
While a D700x might be 3-12 months to never away (who knows) - 5D-2 housings are not properly available yet. The D3x is going to be underwater well before that (are already), so as an underwater photographer the 5D-2 although launched before actually enters our equations later. If the D700x fits the D700 housing (not as much of a guarentee as the D3/D3x) then it could be in the water just a few months behind the 5D-2. We'll see, although I can see it costing at least $1000 to $1500 more than the 5D-2.
I think that the other consideration for each individual is when they have major shoots scheduled. In your case Cor, I can see a motivation to upgrade before Feb!
Alex