You asked, "I mean come on guys, how much resolution do you actually need?"
I think that's a good question, and for me the answer is sometimes I could use a lot more resolution than the D700 has.
Don't get me wrong, I think the D700 is a terrific camera. I agonized over the choice between a D4 and a D800 to replace my aging D700 which now has a bit more than 200K actuations. In the end I chose the D4, but would have preferred a D700s or whatever you'd want to call it, due to "price." I chose the D4 because it fits my needs as a travel photographer who does a lot of wildlife photography too, better than the D800, and it will work well for my other work.
On the other hand the D800 and its resolution beckons. It calls out because it means I could really crop into photos of Kinglets and Yellow Warblers, and still have a large print. It calls out for large prints of landscapes. I'm hoping a trip comes through for me for Antarctica later this year, and for those wonderful "icescapes" the D800 would be absolutely ideal.
There's plenty I could do with all those megapixels. I hope to justify the purchase later this year, but my workhorse will be the D4 with the D700 as primary backup, or second camera.