I think that the Bush administration and campaign feel that the best approach is to let the Left, DNC, and their CBS propaganda minions collapse on their own.
This is a good approach. Comments on this scandal would come off as attacks, giving the Lefties an opening for a counter-attack defense that would play well in the MSM. Right now, trying to defend the forgeries and bias has the rest of the MSM keeping their distance from CBS, Dan Blather, and the DNC.
This story is killing the Kerry campaign - the Bush campaign is wisely leaving the fatal hemorrhage alone.