No, as supplied the bboard module requires a user be logged in. There is an anonymous user created at install time. You could provide a link on the login/registration page that automatically logs the user in as this anonymous user, then redirect them on their merry way. I think the bboard module would work fine afterwards.
Unfortunately, the rest of the ACS is pretty clueless and will present a workspace page for user anonymous, etc, which users might find a bit strange. Probably no big deal for what you want to do. Hey, if they're confused at least they're using your site! :)
