The San Francisco 49ers NFL team have announced plans to build the biggest stadium wireless network so far (source here).
Set to open for the 2014 season the 49ers goal is to support connections for all 68,500 fans simultaneously. The stadium could have anywhere up to 1500 access points, their senior IT Director said.
The 2013 Superbowl had up to 30,000 simultaneous wireless connections during the game (source) and traffic totalled more than 360GB.
It will be interesting to see what technology they use to deploy the network (with 802.11ac and 802.11ad device starting to arrive with high potential throughput). It is said to have a terabit capacity to support all the connections.