InformationWeek's Richard Martin dissects the state of metro-scale Wi-Fi: He offers up some insight gathered across a few cities in California, and has some excellent information from EarthLink about their re-evaluation of how city-wide Wi-Fi can work financially. Among other things, EarthLink has changed its model to turn a profit with 12 to 15 percent resident uptake instead of an initial--and pretty ridiculous--20 to 25 percent. I hadn't seen that initial number before, and I'm glad they've reduced their target.
But this emphasizes what Martin discusses in this article: a combination of city anchor-tenant services combined with residential Wi-Fi is the only way to go. I'd go further and say that any Wi-Fi service provider that doesn't have a strong business offering for broadband wireless over fixed WiMax or similar technology has no hope of turning a buck. The three major early providers--EarthLink, Kite, and MetroFi--all expect to sell business services.