While I don't want to take anything away from FlexCoders and Yahoo Groups, it does feel a bit odd that Macromedia uses this list as well as maintaining a Flex Forum on their own site.
It seems like the response to all the issues is "We don't have any control over Yahoo groups" and "We really don't want to move away from FlexCoders". My gut says this really means that "We have even less control over the forums which provide even less capability today". How much effort would it take to add a few more features to Macromedia Forums so that it simply works for the community's needs? A week or so? I'm guessing it is less effort to make the changes than to overcome the momentum and politics that make change slow and involved. The irony is that Macromedia makes the tools which many have used to build similiar functionality. There is a "corporate pride" card to be played here. Assuming that Macromedia does start using it's Forums more heavily, it should be fairly easy to push new content from the Forum to FlexCoders for those who are slow to migrate.

