An excerpt from a NY Daily News article:
Several sources believe the two leading candidates to replace Tagliabue would be Roger Goodell, the league's executive vice president and chief operating officer, and Falcons president Rich McKay, who is the co-chairman of the league's powerful competition committee.
Goodell's father was Charles Goodell, who succeeded Robert Kennedy as a U.S. senator from New York in 1968. Roger Goodell was instrumental in completing the collective bargaining agreement negotiations and developed an excellent relationship working with Gene Upshaw, the executive director of the NFL Players Association. Goodell also has been involved in the league's efforts to put a team back in Los Angeles.
McKay, an attorney when he first went to work for the Bucs before moving to the Falcons, has developed into one of the most respected executives in the league. Another name that has surfaced is that of Ravens president Dick Cass, who took on a leadership role in Dallas this week in the CBA talks. Cass once represented Cowboys owner Jerry Jones when Jones and the league sued each other in a fight over Jones' sponsorship deals.
One other interesting potential candidate: Secretary of State Condoleezza Rice. In 2002, when she was President Bush's national security adviser, she expressed interest in becoming NFL commissioner if Tagliabue decided to leave.