802.17b Case studies and current usage on Metro Ethernets

I'd appreciate if someone could answer some of my questions: 1. What vendors currently offer support to the IEEE 802.17b standard ? 2. After extensive searching, have found no case studies. Do you guys could recomend any ? 3. If someone had been envolved with 802.17's deployments, what are your thoughts about it ? I mean, the whole process as well as the benefits (and problems) that arose. Thanks !