Left: Snow Leopard, Right: Lion
Apple Stores have been running low on AirPort Extreme, AirPort Express, and Time Capsule wireless base stations recently and new devices have been anticipated for several weeks. It is possible that a name change will accompany a product refresh.
Wi-Fi has been the preferred term for wireless internet connectivity for most of the tech world , and, notably, iOS applications, for a long time, but AirPort has been Apple's name for the various 802.11 standards since 1999 when Steve Jobs introduced the first iBook with Wi-Fi capabilities.
The AirPort name has never really been used outside Apple, but the term Wi-Fi has become more and more popular over the years and it seems Apple has finally acquiesced to popular vernacular.