I concur with your take on it. PMSNBC and NBC can report these rumors, then back off on them and claim they were fed more bad intel from the White House. Then of couse they can imply that the WH leaked these rumors in a political attempt to restore some of the President's credibility.
That way, not only do they get to rip on the WH some more, they give the Rats another opening to take some further shots as well. Just another day in the tag-teaming of the President.