Nikon has three problems they are fixing.
1. The batteries are unsafe and are all being replaced, and out of stock everywhere. They likely are short of safe batteries to put in the production line.
2. The autofocus is reportedly assembled wrong or has bad parts in a whole batch of D800 cameras, and must be fixed or replaced. Affected cameras won't focus.
3. The lockup situation for the D4 and D800 has not been solved, and might be holding things up, but indications are that they are shipping them knowingly with the problem, and hoping that firmare might fix the issue. They have issued a work-around, but users already report that they still have lockups.
These are serious issues that basically make it impossible to use the camera, assuming it happens to you.
I'm sure they will get it all fixed, it just makes the shortage situation worse.