In 14w05b when I place 2 damaged stone pickaxes (have not tested with other items, just started with this version today) I can pick up the "repaired" item, but the previous two damaged items remain, so I can pick up the repaired item repeatedly, and when I close the crafting interface, the original damaged items are dropped as though I never combined them.

As far as I know this may only affect reapiring items, And thus far I have only tested this with stone pickaxes. I just started a new world, and never repair wooden tools, since I move to stone quickly.