The Sept 08 Diesel Progress has an article about Cummins decision to use SCR for it's medium and heavy duty trucks in 2010. There's a new DPF using copper zeolite which they intend to use and supposedly this route will allow better fuel economy. Not sure if this would be applied to the 6. 7, but seems with all the EGR problems it may be a better route.
Couldn't find the online version of Diesel Progress but this link has some info on it:
Cummins to use Selective Catalytic Reduction (SCR) across the board in 2010 | Fleet Owner
Couldn't find the online version of Diesel Progress but this link has some info on it:
Cummins to use Selective Catalytic Reduction (SCR) across the board in 2010 | Fleet Owner