I have to agree that customers should not pay anything for replacing a defective unit so I think I'm lucky that mine is replaced without paying any shipping cost.
I've seen other people say that (if you push the WD folks) they will include a return shipping label.
I think I remember reading the WD people saying in the original thread that if you want to RMA your unit, you arrange it through them and not by yourself. Maybe in that way, you can RMA your unit and not pay shipping cost. I am not sure with this and I'm just speculating so the WD people here can tell me if I'm wrong. I'm saying that because in my case, they are the one who arranged my RMA and I didn't pay any shipping cost. I think there are some people who made the RMA arrangement with them became happy because I saw the WD staff receiving kudos in the original thread so that's also a reason why I'm speculating.
But I also remember that when the WD people said to RMA the unit through them, the reason is so that they can actually receive those faulty units for testing and since it's been months since those posts, maybe they receive enough units for testing so I don't know if they are still accepting that arrangement so I think people should just ask them.