Aero, as I posted earlier, this problem may also be a big problem for those of you who "leased" your car too. Since it would be considered "surface" rust, then I think it would be your responsibility to take care of it. Even though it's caused by a poor design to start with.
When you turn your car back in, I'm sure some dealers will go directly to the "problem area" and point it out to you and say, "You're going to have to pay our body shop to fix that since it happened while you leased it.
It's a relatively easy fix now, but if you let it go, it will turn into something that most people would have to have a "professional" take care of.
We actually lucked out, because a lot of cars have the very same "problem areas" that are completely hidden, and don't show up until it's to far gone for a simple solution to alleviate it.