After about a week of various rumours, the situation is now pretty clear: Harrison Ford broke his left leg on the set of Episode VII, and this required surgery (i.e. a plate and screws). As he recuperates for up to eight weeks, however, Ford may begin filming certain scenes (such as—at a guess—sitting in the cockpit of the Millennium Falcon).
There’s not really a lot more to say except that hopefully this unfortunate incident will be mitigated somewhat by the length of the shoot, which is said to last around six months. Still, it can’t be good, especially for Ford, and it really shouldn’t have happened in the first place.