Whoa! I'm surprised given that the Libby case is ongoing.
Does Libby qualify as a "partisan gunslinger?" (My answer...yes.) Remember? Novak originally said his source is "no partisan gunslinger."
Novak also suggested, although he didn't say it outright, that the source did not work in the WH. And he said that people would be surprised by the name. So unless Novak was blowing smoke back then (which he may have been), look for it to be an individual in the CIA or State Dept.
This doesn't have anything to do with the Libby case. Nothing substantive has anything to do with the Libby case."It's not the crime, it's the coverup" - even if there is nothing to cover up!