Facebook has decided to remove all Discussion Boards from Pages on October 31th, 2011. This is a real sad news for Facebook Pages managers, that are going to lose thousands of topics and messages that were stored in this really popular Facebook Page Application, that reached 54 million users per month during its most active period.
This top score has unfortunately slowly decreased since, reaching 27 million users in December 2010, and recently 22 million users, which is still considerable, but seems not enough from the point of view of Facebook.
The plan for Facebook to counter this decreasing is simply to remove the application from all existing Pages, claiming that the Page Wall is a more comfortable place for commenting and discussing, with a better visibility to page fans and visitors.
Right now, Facebook is unfortunately not providing any way to migrate data which is really silly. There is still one month before the final cleanup, so hopefully, Facebook developer team will provide us a way to export to any JSON/XML format these data, in order to reimport them, either on the Wall of the page, or into any other Facebook-connected forum like XenForo or MyBB.
If you do not know this quite limited (but fully integrated with Facebook, obviously) discussion boards, maybe you should do a tour on our Facebook Forum Software Reviews Page Discussion Boards.