I think Cheney sould be implicated too but mightnot because of the jury and the judge in the case. I also think Libby's lawyers asking questions about a specific person(Cheney) is bogus. Isn't this just like saying they want all Administration supportive, Republican jury members? There is alot of evidence to support a plan between Cheney and Libby to expose the Plames. I hope this comes up in the case. They were saying stuff that would hurt the war effort.
Now the question is, will the judge allow testimony that will stray from the charge of lying about what Libby said to reporters. I don't know and heres why:

Judge Reggie B. Walton assumed his position as a United States District Judge for the District of Columbia on October 29, 2001, after being nominated to the position by President George W. Bush and confirmed by the United States Senate. Judge Walton was also appointed by President Bush in June of 2004 to serve as the Chairperson of the National Prison Rape Reduction Commission, a two-year commission created by the United States Congress that is tasked with the mission of identifying methods to curb the incidents of prison rape. Former Chief Justice Rehnquist appointed Judge Walton to the federal judiciary's Criminal Law Committee, effective October 1, 2005. Judge Walton previously served as an Associate Judge of the Superior Court of the District of Columbia from 1981 to 1989 and 1991 to 2001, having been appointed to that position by Presidents Ronald Reagan in 1981 and George H. W. Bush in 1991. While serving on the Superior Court, Judge Walton was the court's Presiding Judge of the Family Division, Presiding Judge of the Domestic Violence Unit and Deputy Presiding Judge of the Criminal Division. Between 1989 and 1991, Judge Walton served as President George H. W. Bush's Associate Director of the Office of National Drug Control Policy in the Executive Office of the President and as President Bush's Senior White House Advisor for Crime.
Judge Reggie B. Walton