First, let's clear up something, Bloomberg was the first to actually print that Cheney was the focus. WaPo followed. Still have yet to hear from WSJ. Rawstory had it backwards, they predicted WSJ, Bloomberg, with WaPo to follow. Maybe they messed up every one's playbook. Way to go RawStory.
Second, lots of speculation on who flipped. Here is my completely invented guess: Karl Rove. Why on the flip.
First, you have to start with the assumption that Rove and Cheney are on the outs. You've seen it reported, you've seen Cheney be non-existent, its a high probability. Second, you have to notice that Bush these days is playing the old Clinton triangulation strategy to a tee. The Miers appointment was designed to push Bush to the center, not the right. Probably to give him enough distance so that he can change strategy in Iraq. Who knows the real reason. Its a fact that he's been moving away from the hard right though. Third, Rove came back to Fitz on his own! He wasn't called in. Fitz sent him a "are you sure, cause I'm not offering a deal" letter when Rove said he wanted to come back.
So here's the theory, Rove decided the only way to get Cheney out of the way was to get him out of the way. I mean really, aren't you a little surprised Cheney is still there? Weren't they supposed to put in a "successor" by now? Now with the fighting from Cheney on Rove's re-working of the ol' Dick Morris strategy, Rove wants the guy out for good, and the guy won't leave. So Rove decides, instead of letting Scotter talk the fall, which was probably the end game (hey, they'll all get pardons anyway), he'll turn on Cheney and force the guy to be named as an unindicted coconspirator. A press conference later, they'll ask for Cheney's resignation. See ya later Dick. Now they've got two years to fix Iraq, get gas prices down to a reasonable level, and prep the new VP for the presidency.
Again, just a guess, but I really think Rove did it. Fitz's letter gives it away, I think. He's telling Rove, I'm offering no deal here, but if you've got a bigger fish for me, I'm interested.