One of the issues arising lately at my customers is how to protect sensitive information published on Sharepoint. IRM is the answer altough it doesn't cover 100% of customers' requirements. IMHO, IRM could be better marketed as "document pimp protector" than generic DRM.
http://blogs.msdn.com/gayanpeiris/archive/2008/03/24/information-rights-management-with-sharepoint.aspx