Facebook did made announcement about the new messaging system which is like a Unified Inbox for all your Facebook Messages and since its ain invite based you need to go to this url and request for an Invite instead of bouncing around the Internet to either buy an invite or go crazy about it unless it’s really going to solve a worth-full purpose for you.
IMO, Facebook new so called Email System is a Unified Inbox which BlackBerry users had used from a long time. You get to see all SMS, Configured Email and Updates from apps at one place. This is something which is coming to iOS 4.2 also. So it’s not something which will surprise you very much but if you are Facebook Fanboy you will love using it.
As a matter of Fact Facebook itself is not calling it Email System but the New Messages which has Texts, Chat and Email together at one place. More like Facebook Message System got redesigned.