Seems the big boy GM 200 got caught in a picture:

http://www.guru3d.com/news-story/nvidia-maxwell-gm200-flagship-gpu-caught-on-photo.html


Seems it'll initially be released in quaddro cards with a 12 GB memory capacity, so that suggests a 384 bit memory bus, and it isn't using HBM like the 380X will....Given that is is a quaddro card ( render farms for special effects in movies etc..), expect a price tag to match and it doesn't state when a Geforce version will be released.

Rumors suggest it's 620mm^ which is huge if true (about 25mm by 25mm square), so if would be the largest GPU Nvidia has made so far....GK110 tipped the scales at 562mm^