It could happen. The Tories are quite happy to ditch a leader. Cameron is uninspiring. In tough times, people like charismatic leaders.But the election is scheduled for 2015 and it is more likely that the Party will wait and see how badly Cameron does then before dumping him, unless the polls show he is personally far more unpopular than currently and that is dragging the Party down.
Bit difficult to know exactly what Boris thinks on key matters.But he does give the impression that he's not a great one for compromise and the coalition.
He has only the experience of Mayor as an administrator, not in government, but that may not count for much . Obama, another charismatic figure, had none and Mrs Thatcher had little. I think Boris would make a better PM now. Cameron seems far too wishy-washy and not a person whom people would choose to follow in difficult times.