This yet-to-be-designed complex would hold 45,000 permanent seats and 35,000 temporary seats for spectators. According to the new venue layout plan, the OSC would become the center of swimming and diving events, which were previously designated to be held at George Mason University. The center would also be designed to accommodate track-and-field, boxing, handball and archery competitions.

Other amenities would include a centralized press and media center, an international broadcast center, spaces to contain pavilions for sponsors and live entertainment. The addition of a new complex was just one facet of DC 2012's 256-page addendum. "Building on the strength of our initial bid, the addendum continues to focus on utilizing existing venues and maximizing mass transit, while leaving an appropriate legacy for both the Olympic and Paralympic Movements, and our local community," Washington, DC 2012 president AND CEO Dan Knise says in a statement. "What was a good bid is now a great bid, one that we're confident has what it takes to win."

No price tag for the proposed pavilion was released. The US Olympic Committee decides in November, which of the four competing cities will represent the country in the worldwide competition. The International Olympic Committee's decision on the location for the highly anticipated 2012 events is expected in 2005.