See HERE if you use Nikon's software for the updates.

Capture NX2 goes from v2.3.0 -> v2.3.1

ViewNX2 is updated from v2.2.5(32bit mode only) -> v2.3.0 in both 32bit and 64bit now.

If you're using 64bit CNX2 and used the Picture Control Utility, it couldn't be accessed in 32bit ViewNX2.
The update to 64 bit ViewNX2 should resolve this.

I think the update for CNX2 is mainly for the new camera arrivals, but of course there ViewNX2 has the added install option for 64bit(I think only in Windows tho?)
There are a few other quite insignificant tweaks, but now in ViewNX2 there is new a 'save as' option under the File menu(where there never used to be one).
Only problem is that it's quite useless in many ways.
It seems to only save as the same file type as the original file .. that is, it's not quite the same action as in CNX2(where you can instantly and easily save in a different format to the file you are working on.. ie. quick conversion!
No!!.... It only saves the file as another version.
I just tried it on an NEF, and tried to save the NEF file as a jpg( ie. quick conversion) to see if it did the conversion. But it saved the NEF file as blahblah.jpg.NEF!!

I can see the point, in that what it's doing is to save an image file but without destruction of the original.
That is, if you want to save a quick version of a file say for comparison purposes, 'save as' saves the file you've edited to a new file, but leaves the original file as per the last save point .. whether that is in original condition, or edited on a prior session.
Also quite annoying is the lack of the keyboard shortcut via Ctrl+Shift+S to do a 'save as'.
Ctrl+S gives us a save on the currently active file, but traditionally on a Windows box, Ctrl+Shift+S opens up the 'save as' dialogue box (as it does in CaptureNX2).

Actually, I have really checked to see if the function of the Shift key can be changed.
I'm guessing that you don't get the keyboard shortcut, because the Shift key is tied to the instant 100% view feature (in default installation, but configurable to 50%, 200% and 400% view, but not with the ability to turn it off!). Pressing the Shift key, the image is instantly zoomed into 100% pixel view at the point where the mouse is on the image.

Anyhow, VNX2 2.3.0 does feels a bit nippier, but I've been one of the lucky ones where both my installations of Nikon software have always seemed to run quite fast anyhow.

The few conversions from raw to jpg and tiff that I've done, seem to save a touch quicker now.