They won't send it anywhere. Our local Apple Store has drawers full of replacement keys (seriously). Based on your picture it should take about 10min to replace those keys, and be covered under warranty.
I can agree that my Dad has his less than 6 month old PBG4 in over Christmas and besides the store dropping it and having to send it off to Austin for more repairs than originally anticipated (it went in with a bad hard disk and left after having the top and bottom casings, LCD, VRAM, and other components replaced due to the "oopsie"), I did notice some ink marks on the function keys the guy couldn't wipe off. In less than 20 minutes, he returned from the back with a new keyboard in place.