I can imagine the pressure on Nikon to produce FF will be considerable after it's release to market.
How is the release of a new 1.3x crop model by Canon a reason for Nikon to go to 35mm format? It points in the opposite direction, likely ensuring that Canon's top selling pro model will continue to be in a "crop format" not much larger than DX. (From Canon production figures, the 1DMkII has outsold the 1Ds models about 2:1).
One message of the EOS-1 D Mk III is a point that Canon has made repeatedly in recent documents: in digital, formats like 35mm/1.3x (and 35mm/1.5x) have a persistent, substantial cost advantages over 35mm format, big enough to be significant even to professional usage.
The 15% linear size difference (about 0.4 of a stop) between the DX and 1D formats seems too small to get very excited about.
P. S. On the subject of progress in making larger sensors without the expensive complications of "multiple pass" needed for the 1Ds sensors: the new 1DMkIII sensor is slightly smaller that of the 1DMkII
: 28.1x18.7mm vs 28.7x19.1mm, and Canon says that this is "the largest sensor that can be made in one pass using cutting edge semi-conductor manufacturing technology".
The 1DMkII sensor has been made in one pass since its release three years ago, suggesting no increase in maximum "one pass sensor fab." size in that three years.