Hi, I caused a bit of a stir in the forums when the D800 launch was due; mainly because I stated that I was happy with my D700 and in fact purchased a second in preference to waiting for the D800.
Why did I do that, mainly because I love what the D700 does for me, especially it's proven low light track record. My belief is that less pixels on a sensor means bigger pixels! Bigger pixels = better low light sensitivity.
But at the end of the day, it's a personal choice and that depends on what you photograph and how you photograph.