I was a fan and admirer of Mr. Russert, although I was fairly tough on him for his role in the Plame leak and the ensuing Libby trial.
Very briefly on the trial - David Gregory of NBC News was alleged to have been informed of Ms. Plame's CIA affiliation by then-press secretary Ari Fleischer; Special Counsel Fitzgerald did not push for Gregory's testimony and Gregory has never resolved this, to the best of my knowledge.
Andrea Mitchell, also of NBC News, was covering every other aspect of the Wilson-Niger trip and claimed to have received a leak about Ms. Plame, but later back-tracked. Special Counsel Fitzgerald never got her testimony, either.
Tim Russert, in his role as Washington Bureau chief, claims he would have been passed the tip if either Gregory or Mitchell had received a Plame leak. He also insisted in court that he had not received a leak or relayed such a leak back to I. Lewis Libby, but I speculated as to the circumstances which may have led him to lie under oath.