I expect Canon will not be able to deliver a sensor+electronics matching the current Nikon D7100 sensor in terms of IQ. Not in resolution (20 vs. 24 MP) and probably even less so in DR across all ISO settings starting at base ISO nor in Hi-ISO Noise.
My prediction is that the 70D will lag behind the D7100 in terms of DR.
In terms of ISO/noise, however, the 70D should be able to match (and maybe even exceed) the D7100.
The D7100 got a high overall DxO score because of its high DR.
But if you look at the ISO/noise measurements, it's not all that good.
The 70D doesn't need to be much better than the current 18mp sensor to match the D7100 in ISO/noise.
Of course for DR it's pretty certain that D7100 will be a clear winner.