Esme Vos details the just-released RFP for the city of Chicago's Wi-Fi network at Muniwireless.com: The highlights are that the city requires wholesale resale of the network; the city won't provide dollar one for the network; it must be ubiquitous and egalitarian in coverage; there is no access to the city's fiber infrastructure; access to city facilities for mounting is non-exclusive; any form of free access to residents or visitors isn't required for a winning bidder.
Muniwireless.com also has the PDF for downloading, as Vos points out that the city requires registration as if you were to be a bidder on the network just to read the RFP.