Yes but the inventive have figured out what pins work for the wireless and put wireless functionality in - see The 21st Century Digital Home: Arduino Esplora interfaced to an Xbee Radio for some details.
It's easy enough to add but also, it would have been easy enough for them to put it on-board or put on surface mount pads between the display pins where you could solder one on (something like a nRF24L01 in SMD package would have been ideal - http://www1.dealextreme.com/productimages/sku_149253_1.jpg)
