Nobody will be "charged", because 'slander' is not a criminal offense.
And even in a civil matter (case) "slander" against a 'Public Figure' (Dubya) is almost impossible to 'prove'. i.e.; win. And with a politician its near impossible. It also has to be proved that irreparable harm was done by said "slander". And by Dubya winning the election, well that kind of shoots that down.
Don't misunderstand, I agree with your outrage, but Slander or Liable isn't an option. I'd think the forging of government documents would be the way to go but that would be that Burkett guy (probably). Legally Rather, Mapes and CBS are off the hook.
If a civil proceedure is provoked, then subpoena power, disclosure, depositions, written interrogatories. If the crowd at CBS are sued, then they will all get their own lawyers, and each of their personal interest are different, and you divide and conquer. Get them pointing the finger at each other and the truth may be disclosed. Short of that, I don't think the heat has been turned up enough. If criminal justice would impannel a grand jury, then we would find out who the turd in the punch bowl is. I pray it would be so.