Fear not. They're just picking at straws. Call it wishful thinking on their part. Rove is NOT stupid, and 2 liberal reporters would NOT go to jail to cover for Karl Rove!!!
I've seen that sentiment a lot, and I'm not buying it. Whatever you think of their individual politics, no reporter who wants to remain in the profession is going to burn a source as big as Karl Rove.
And it's bigger than Rove alone -- if they gave up an anonymous source, they'd have no luck finding anonymous sources in the future.