This is not a perfect world, but in the interest in clarifying a question that has been asked a few times:
EzineArticles.com has 3 MEMBERSHIP SYSTEMS.
Membership system #1 is the Author membership system.
Allows you to send in and manage your articles.
Membership system #2 is the Forums registered member system.
Allows you to participate in the EzineArticles.com/forums/
Membership system #3 is the Registered Commentor system.
Allows you to post comments to any article at any time.
There may be a day when we are able to tie all 3 of these systems in together, but we felt it was more important for us to get the base functionality out the door than it was to wait until the perfect day arrived when we could offer them all together in one system.