Dalida, the only advantage of the D4s vs the D800(E) is the higher frame rate (up to 11 fps vs up to 4 fps), which you'd only need for capturing a cheetah in full speed, with a lot of luck; I'd definitely go for the Nikon D800 or the Nikon D800E (if you want a certain plus in resolution), reason: contrary to the preceding post, the sensor of the D800(E), currently the best in the market, beats the D4s sensor (albeit slightly, probably hardly visible) in all criteria, like signal-to-noise-ratio (low lighting conditions), dynamic range, tonal range, color sensitivity, as empirical and objective scientific tests have proven. The Nikon D4s is called pro because its target buyers are photo journalists, especially sport photographers. All 3 models have 51 AF points.
Mind the battery grip, what you assume is not correct: the D7000 has the MB-D11, the D7100 the MB-D15, the D800(E) the MB-D12! A battery grip is not a must, you can shoot many many hours (days in normal usage) with the integrated battery.
The claim of the preceding post that the D800E sensor is more prone to sensor dust gathering is nonsense and not proven by facts, both the sensors of the D800 and the D800E have 3 elements (2 low-pass filters and 1 optical element) in front of the sensor (although working differently in both models). (I have had experience with the D4s and the D800 and own the D800E and have taken more than 10,000 pictures with it, with frequent lens changes, no sensor dust at all).
With the ultra-high resolution of the D800 and especially the D800E, the limiting factor for resolution is sharpness of lenses, so you should go here for the very best in Nikon and Zeiss (Otus). And when shooting manually, you'd be advised to use as shutter speed for static objects at least 1/f*1.5 due to the ultra-high resolution.
Another advantage of the D800(E), given its 36.3 MP: you can crop as you wish.
The D800s will probably be presented (not launched) either in September or in January 2015, maybe later; availability usually shortly, up to some weeks, after presentation. And again no: it has not much in common with the D4s, just minor AF improvements; main features: no anti-aliasing filter (just like the D800E), 5 fps (about D800 level), SRAW (new), price between the D800 and the D800E.