Ladies and gentleman, I can finally say this. The GM200 is here. Maybe not exactly at your doorstep, but pretty close.
The leaker who is probably working for the manufacturing company revealed the GM200 engineering board (180-1G600-1102-A04). That said the The Big Maxwell will use PG600 board.
The mysterious card has ttwelve Hynix H5GQ4H24MFR modules, clocked at 7 GHz. Together they form 12GB frame buffer. This is probably the same card we saw in GPU-Z database, the Quadro M6000. NVIDIA is known for reusing the same boards for various models, so this could very much be the TITAN X/2/Ultra board as well.