I shoot video all the time for my job. What I am most looking forward to about the D800 (aside from finally moving to FX for my stills) is the ability to use Nikon glass for my video.
I am also hoping that the stated UNCOMPRESSED video through HDMI is accurate and that the supporting gear for this doesn't cost an arm and a leg.
I am not a video 'expert', but I have shot/or been exposed to quite a few video platforms (a video camera under $5Gs I believe might get you substandard results compared to a really nice lens on the D800) .. of course this is all purely speculation. The RED Scarlett or the Canon XF305 for example ends up surpassing the 15G range immediately once you add all the components they require.
I think this may be an all in one answer for my needs and stay under 5 grand ... time will tell.
I agree that you need to support the camera with some pricey gear though if shooting serious video. I also agree that handheld wont work as the stabilization surely cant compare to a good camcorder.
I also think the ergonomics of shooting video with a nice camcorder feel better than shooting video with a DSLR.
Anyway ... here's to hoping =) ___________________________________________________________
Reality is merely an illusion, albeit a very persistent one. - A. Einstein