Interestingly, today I went to the mall with my D800 and took a few pictures HANDHELD. I averaged about 1/80s at f/4 with a 50mm lens at 400 ISO. They were sharp as a tack. Of course, I was careful in my hand-holding technique.
I did this because I have a wedding coming up in May and I wanted to see how the camera would handle in a handheld environment.
I also shot some nice handheld portraits today. Wanna see some? They are sharp!