Not that surprising, really. A lot of franchises have been opening WAPs to customers. Starbucks, for example, has been doing this almost since the beginning of wi-fi connectivity. And some Mickey-D's in major metro areas have had wi-fi for laptop/PDA users for a while now.
Though I wasn't aware that the DS had 802.11 capability - I thought the interlink was based on a proprietary implimentation of Bluetooth.