We at Fog Creek had envisioned that FogBugz.SE could eventually provide you with all that you need-- plugin developers could have tags for their plugins and generally be owners of all questions with those tags, thus providing support, getting feedback, making announcements, etc. This has the advantage of automatically making the plugin community visible to the FogBugz user community. Ditto for general FogBugz ecology.
E.g., I might have a question entitled 'URL Trigger Plugin", tagged 'plugin' and 'plugin-url-trigger', I would keep it updated with the most recent news on URLTrigger, and I could gather feedback on URLTrigger via that mechanism. I'd generally monitor FogBugz.SE for anything containing my URLTrigger tag, and thus gather bug reports and provide support via SE. Some of this behavior has already emerged on its own, such as the 'workflow-plugin' tag, etc.