Had a quick play with it yesterday, I can see it being a good thing in some situations.
After I managed to figure out where the images were going to when they left the camera it was simply a matter of pointing View NX to the folder -- My Documents / ControlMyNikon v2.9 / Images and they appear in real time straight after the shutter is pushed ready to be viewed at 100% on the pc screen. Very handy for checking detail and colours at a much higher resolution than the on board lcd can give.
I was using the D200 and it seems there is now way to achieve focus through the program when using the AF ON button.