The ISSS World web site is one of the places where members convene, but it doesn't have to be the only place!
On Google Plus, there's a Systems Sciences Community where content is open on the web. Reading doesn't require registration. Posting content and comments requires a Google Plus identity.
For those who use Facebook, you can the Systems Science group membership to both view and to post. Just ask to join, and one of the moderators should approve your request.
These alternative venues are less formal than the official news on isss.org, and are tracked by many members of the society.