I agree with Bryan that Bernanke is an excellent choice. He is knowledgable and articulate--just the other day I referred econlog readers to Bernanke's overview of recent productivity developments.
Ben was a year ahead of me in grad school at MIT. He seemed very mature.
Because of his maturity, I think that Ben stands head and shoulders over other high-caliber academic economists as a potential leader at the Fed. He will be able to motivate the staff, achieve consensus on policy, and attain credibility and respect from the financial community and world leaders.