New Fitzgerald grand jury - what it means

Washington Post explains, "Experts said that Fitzgerald is not trying to shore up his case on Libby. Under court rules, Fitzgerald cannot use a new grand jury to gather additional evidence for an indictment he has already brought, or to wrap up unanswered questions in preparation for Libby's trial. He can only call on a grand jury to hear evidence if he is considering new charges against another person or additional charges against Libby."
Update - Nov 21:  Andrea Mitchell's inconsistencies re Wilson-Plame info