Ginni Rometty

From PepsiCo to Avon to Xerox, these women are responsible for some of the biggest companies and brands that consumers touch and feel everyday. And this year, there's a new No. 1 on Fortune's list of the most powerful women.

IBM has realigned its executive suites and expanded the roles of four of its top managers, according to an internal memo sent to employees Monday -- a move that potentially paves the way for one of them to become the successor to CEO Sam Palmisano.