John Kranz has the following notice up at CSW:
ADMIN ALERT: The CSW Forum will be off-line starting Wednesday AM for a forum software upgrade. The downtime is expected to last several days. We ask for your patience as this update is critical to permit for future enhancements to the forum itself, in order to improve services. Our other sites will be available during this time, including the CSW Newsdesk and Social Network.
To my understanding this is because they are doing a MAJOR forum upgrade including a new engine. He says elsewhere that while the UI won't change yet this is the first step in an extensive modernization of the site.
Just wanted to let people know so when it goes offline tomorrow they are not caught unawares.