Not enough time so far to explore all the possibilities. Used it as a Video backup at a recent wedding where I was the Videographer, stunning quality although takes some getting used to as a video camera. I never expected to be converted so easily to a DSLR for video, but there we are. I am about to sell some seriously bulky Canon HD Video equipment and travel light when doing video in future.
Worried that the resolution might show up lens shortcomings, but seen no obvious evidence so far. I do print to A2 and the file size is a major boon. I have added a D4 and held onto my D3s but see the D800 as my new "travel" companion. I loved my D700, but I'm afraid there is a new girl in town. It may be imagination but you can almost see the quality on the rear screen. I don't know if anything can be 10 out of 10 but it certainly seems that way.