First let me state that I know the D800e is an entirely different camera designed for a different use than the D3s or D4; so don't shoot me.
I currently shoot w/ a D3s and D700. I am a wedding, portrait, event, landscape, and pj photographer. I am going to start shooting some sports, mainly football.
I like my D3s, don't love it though. I find that focusing takes some time in low light and caucasian skin tones come out a little red. Also I am beginning filming so the D3s video quality is sub-standard.
I have shot the D800e for an extended period and greatly appreciate the extra pixel resolution for my landscape and architecture work, however it is not the workhorse, all-around, do-everything that the D3s is. I do like the lightweight of the D800e though, after carrying a D3s w/ a RRS L Bracket and a D700 w/ a battery grip and a RRS L Bracket for 12 hours or longer, the compact minimalist body of the D800e is pure joy.
I have yet to shoot w/ the D4 for more than 5 frames, but I do like what color it produces. However, I am not impressed with the 4mp sensor upgrade from the D3s. That and its $6k price tag.
Anyone who has migrated from the D3s to the D4 or shot the D4 enough to "not" migrate, would you mind sharing your opinion and experiences?