I think for the 2012 Photokina show Nikon will only announce the Nikkor 1 18.5mm f/1.8 mirrorless lens and the D600 DSLR full frame camera. No new DX cameras, Nikkor lenses or Nikon 1 V2 mirrorless camera will be presented at the show (the new 800mm f/5.6 lens will be on display). I also believe that there will be at least one more product announcement after Photokina and before the end of the year.
If you are interested what other manufacturers have planned for Photokina, check this recap on PhotoRumors.
