The project was a partnership between the City and a private company (Metro-Fi), who agreed to put up access points all over town with an emphasis on public spaces, parks, and popular gathering spots.
Access to the network was free, but included HTTP-injected iframe ads and frequent interstitial ads between pageviews. Compounding the woeful experience this provided, the network itself was very slow. Checking anything beyond the complexity of Reddit could become a multi-minute affair. The company also offered Metro-Fi Premium, an ad-free version of the service for around $20/month. It was positioned as a replacement for Comcast or Qwest, but no one took it seriously.
The reach of the network was also quite poor. I could almost never get a signal or acquire a connection if I found an AP - it's the sort of thing you'd regard as the last resort if there were no open APs nearby.
In the end, Metro-Fi went bankrupt, defaulted on their contract, and left the city littered with dozens to hundreds of wireless antennas atop intersections, utility poles, etc. that the city now has to pay to remove (the cost of which was estimated at something like $70,000).
(An alternative project called PersonalTelco.net, a non-profit gang of Portland hackers who wanted to bring fast, free access to popular gathering spaces like coffee shops, bookstores, etc. had much more success in bringing fast access to some of the most popular spots, but I wouldn't include it as a "metro wifi" project in that it focused on a few spaces rather than blanket coverage.)
Several months ago Clear (a partnership between Intel, Sprint, and Comcast) launched WiMAX across the metro area. It's fast. Real-world tests (read: dude with his laptop at a bookstore) came out on par with a DSL landline. It's cheap, at $20/month. And because each antenna has roughly the range of a GSM tower (in fact, most are mounted upon them), the network's range is much greater at a fraction of the cost. And while most laptops lack integrated WiMAX support, people are quite happy to plug in a USB adapter.
It's still too early to see how Clear will fare in Portland, but these factors give them a much better shot at success. I only wish the city would have had such foresight a few years ago and invested in WiMAX instead of wifi.
Can anyone from Atlanta comment on Clear's performance and public opinion?