Of course for DR it's pretty certain that D7100 will be a clear winner.
I don't think Canon cares about DR vis-a-vis the Nikons ... that could only be so because the most of the users of the cameras also don't care about DR ... I'm no longer sure if I should care either.
More DR in canon cameras is certainly welcome, but it isn't all that matters.
The 70D needs to be compelling and different enough to get lots of 1xxxD, xxxD and xxD users to upgrade to it. The 60D was very underwhelming in that regard.