They have no replacement keycaps or hinges in stock for the new MBPs. I too have a problem with a key (for me it's the down arrow), and they told me there's nothing they can do besides have me order a new machine online and return the current one when it gets here...which isn't until January 2nd.
The genius was able to diagnose the problem with the key, and said he *could* replace it if he had the parts in stock, but they have no parts, no way to order them, and no idea when they'll get them.
It's just ridiculous that it takes another month to get a laptop. I'm not sure what Apple was thinking with the Macbook Pro...