what will facebook do with fb.com domain ?

In September ,fb.com domain has been sold to an undisclosed buyer by the American Farm Bureau .However, Domain Name Wire has revealed that the domain’s whois has been updated to reflect that Facebook (Facebook) is the domain’s administrator.
It is said this domain using in Facebook internally ,but doesn't know what facebook gonna do with it .
Most likely, Fb.com will become the e-mail domain of the company’s 1,400+ employees. Yahoo does something similar; its staff uses @yahoo-inc.com e-mail addresses instead @Yahoo.com in order to avoid confusion between its employees and the hundreds of millions of users of its e-mail service.
By the way ,Facebook has been updated their message system to work like email . Maybe in future ,we can use email with @facebook.com ?