D800 and holy trinity vs. primes?

When i got the holy trinity lineup (was using d90 at the time) I was blown away by clarity, sharpness and richness of color. The f/2.8s still perform flawlessly on d800, but i am wondering if d800 is pushing their limits at f/2.8? Do you think the top of the line primes (Nikon, Zeiss, etc) at f/2.8 would be visibly sharper than these zooms? The f/2.8 nikon lineup is so good that I'll dare to say that: unless you need f/1.4 or f/2.0 there is no reason to use primes over f/2.8 zooms. This was true for me on D90, but does the 36mp sensor rejuvenate the need for primes at f/2.8 and slower? I know that some primes can be cheaper and i know that zooms can be much more convenient; this thread is about IQ only, let's imagine we all won 100 Million dollar lottery.