I just took a look at the buyers guide, right now there is one body (D300s) and two lenses (300 f/4, 200 f/4) that are due for an update (the 80-400 update needs to be acknowledged). Sure looks to me like the whole range is as up to date as it is ever going to be.
At least two of those updates might never arrive. The D800 is a great professional DX camera and the 70-200 f/4 arguably makes the prime unnecessary. The zoom is $1400 so a prime would not fetch more than $900. It is out of stock at all the shops so either an update is imminent or (more likely) there will be no replacement.
A 300 f/4 AFS with VRII or III makes a lot of sense, modern sensors make the extra cost and weight of the f/2.8 unnecessary. But right now that is the only lens left that screams for attention.
All of which makes guessing 'where next' a lot harder. Predicting an update to the 80-400 was pretty easy, it had to happen some time. It is pretty obvious that a D400 is likely simply because there is nothing else needing immediate attention in the DSLR range. A D4x with a higher resolution sensor is another obvious possibility. But that is only two bodies, both essentially a sensor swap to an existing body and one lens. So what else are we likely to see?
One way to predict is to look at what Canon has done. Nikon has matched Canon's f/4 zooms and 800mm bazooka. So a 50mm f/1.2 is one option. Another likely option is more lenses for the Nikon1 system and maybe even some more DX primes.