Taking the top job at Kraft was a homecoming for Rosenfeld, who spent 22 years at the company, then took a detour to PepsiCo to head the Frito-Lay unit. Now back at Kraft, the world's second-largest food company (2005 revenues: $34 billion), she is facing major challenges. Several years into its restructuring plan, Kraft's sales are sluggish. Rosenfeld's next move: preparing for the widely expected spinoff from parent company Altria.