As @mibbz states, the 767s will be returned as the 787s come into service. There is still need for them as routes are maintained or expanded. The 787 doesn't even fly to Paris until 1 June 2014.
The 767s might be re-deployed to some sectors esp African destinations despite high operating costs if the lessor reduces the leasing costs thus the overall cost to KQ remains competitive. The lessor doesn't want these planes back either! So it makes more sense to reduce the leasing price to KQ rather than have it sit around in a yard somewhere.
Greedy when others are fearful. Very fearful when others are greedy - to paraphrase Warren Buffett