I think they did, but it was too late. I say that because when I bought the iPhone 4 online, they pushed me this rubber ring to go with the phone. It's called "bumber". Horrible. Why would I want that? I just use a screen protector on my phone, I think the thickness (or lack of it) is what all these devices are about.
That has never happened before, not dock, av cable or anything, certainly not a case or skin. And apparently this rubber band does help a little, but some people challenge even that.