According to this article it may be possible for Apple to join the auction for the 700 Mhz signals. What does this mean? Well, if Apple should indeed be planning on bidding on this auction Apple could become a network operator and ditch AT&T as a partner for selling their iPhones. Other potential bidders in this auction are Google, eBay and DirectTV amongst others.
A bid of 9 billion $ is expected to win a portion of the spectrum for a nationwide network. Considering Apple's huge cash position of 14 billion $ this is not the unthinkable.