It is out, and while I don’t really enjoy Nikon bashing because I think they make great stills camera, I have to say that I am not impressed. While it is going to be a great tool for photographers who wants to be able to shoot occasional clips, its lack of manual control over fps, short HD clip duration (5mins) and restriction to 720p, is really limiting!
On the other hand, the high ISO is really impressive, but unless you are constantly shooting in the dark, it is not a key feature as it used to be before the ISO 3200 era.
Basically, the current generation of HDSLR belongs to Canon, even more so with the upcoming announcement on Oct 20 of the expected 1DMarkIV.
Some reading about the D3s: