UPDATE: While there has been no confirmation that the former World Title/Big Gold Belt is going away, there has been an interesting change on WWE.com. In the champions section of the website, only the WWE Title is pictured under John Cena. Prior to last night's RAW, both the "WWE Title" and "World Title/Big Gold Belt" were shown with Cena, since together they have been representing the "WWE World Heavyweight Title".
UPDATE: Following last night's edition of Monday Night RAW, there is a lot of speculation that WWE will be retiring the World Title Belt.
After Ric Flair's segment, John Cena made his way to the ring and handed the belt to, telling him to keep it. Flair then left with the belt. JBL later noted that there is only "one title now" but there was no official announcement of a change.
More details as they become available.