Rivalry between Powell and Rice?

This report from CNN, "Powell and Rice: Opposites, but Not Opponents," speculates on a possible rivalry between Colin Powell and Condoleeza Rice for control over the Bush administration's foreign policy. Both deny this, but it would hardly be the first time. Many of us recall the competition between Secretary of State William Rogers and National Security Advisor Henry Kissinger under President Nixon, and between Cyrus Vance and Zbigniew Brzezinski under Carter. It's easier for a president to listen to advice coming to him from the White House Office than from the entrenched bureaucracy in the State Department. The rivalry between Secretary of State and National Security Advisor seems built into the very structure of these two somewhat redundant offices.