http://en.wikipedia.org/wiki/Chief_Justice_of_the_United_StatesDuties
In addition to the duties of the Associate Justices, the Chief Justice has the following duties:
- If the Chief Justice is in the majority on a Supreme Court case, he or she may decide to write the Opinion of the Court, or may assign it to an associate justice of his or her choice.
- The Constitution stipulates that the Chief Justice shall preside when the Senate tries an impeachment of the President of the United States.
- Two Chief Justices, Salmon P. Chase and William Rehnquist, have had the duty of presiding over the trial in the Senate that follows an impeachment of the President – Chase in 1868 over the proceedings of President Andrew Johnson and Rehnquist in 1999 over the proceedings against President Bill Clinton.
- Presides over the impeachment trial of the Vice President if the Vice President is serving as Acting President (not a Constitutional responsibility but a rule of the Senate; no Vice President has been impeached, and none has been Acting President for more than a few hours).
- Administers the oath of office at the inauguration of the President of the United States. This is a traditional, not a constitutional, responsibility of the Chief Justice. All federal and state judges, as well as notaries public, are empowered by law to administer oaths and affirmations.
- Serves as the Chancellor of the Smithsonian Institution.
- Serves as the head of the Judicial Conference of the United States, the chief administrative body of the U.S. federal courts. The Judicial Conference is empowered by the Rules Enabling Act to promulgate rules to ensure the smooth operation of the federal courts. Major portions of the Federal Rules of Civil Procedure and Evidence have been adopted by most state legislatures and are considered canonical by American law schools.
Some of it is not that important but if we managed to impeach Bush it's kinda messed up to have Roberts in charge. Hell it would be nice NOT to have the slot filled for a few months because the fill-in until a replacement is found is the senior justice and that's John Paul Stevens