On a bright side, it's not a serious injury and her foot is not on a cast. The bone has sustained minor bruise, so to speak. She should be fully recovered by the Olympics but it's inevitable she has to make a difficult adjustment to her roadmap to Sochi in regards to training, physical conditioning, tuning the programs, etc.
EDIT: 6 weeks of intensive rehabilitation is based on the most pessimistic projection; she could be healed as soon as in 3-4 weeks. A cause of the injury, according to the sources, is from fatigue. No injuries to any ligaments or joints which could have been very serious.
EDIT 2: It will take least 6 weeks to prevent any possibilities of relapse and return to her top body form.
As I understand it the metatarsal are the 5 long bones leading out to the toes. Do we know which of the five or are they all fatigued?