i had ordered an airport extreme last week, it still has not shipped so i called apple, and they said they were waiting to ship the new one. I said what new one, they said a new airport came out today. I didnt think she was right because nothing was said about this today. But it is true the old model number is MA073LL/A the new one is MB053LL/A She said i would recieve an email stating that they filled my order with the new part # what is the difference ??