The first of the A340-600s has already left the operating fleet. The other two will leave by the end of Autumn.
The rest of the A340-300s are here to stay apart from maybe the 4 which are leased. CX fleet figures quoted by management for 2012 indicate 11 of the 15 A340-300s still in the fleet.
As for JNB, I believe the 744 is put on at the start of the northern hemisphere winter schedule. (end of October I think it is?)