What, you don't visit NR regularly? You gotta work on being a fan boy more. 
http://nikonrumors.com/2012/08/30/updated-specifications-for-the-nikon-d600.aspx/
So they are claiming 16-bit /processing/ which refers to the width of the DSP pipeline. I'm definitely not expecting 16 bit per-pixel DR very soon. And when that day comes, we'll need better than 16-bit processing to make use of it. We'd also need a new photoshop, which only uses 15, but would need a complete redesign from the ground-up anyway.
