The LSM is scared silly about Perry. They think he could beat Obama handily, and are wishing to keep Palin viable and encouraged, hoping that she will run, and that she and Perry will cripple each other in the primaries and caucuses.
Bingo.
I think kevkrom’s explanation is correct. Occam’s Razor: the simplest answer is most likely the correct one.
“The simplest answer in this case is that the left-wing media is annoyed by the amateurishness of the recent attacks, and their too-early timing. They have to condemn them to protect their own reputations.”
Plus, the MSM is starting to fear they have gone over the top, and are worried about a backlash.