Pokemon Delta Emerald has been trademarked by Nintendo in Japan, Esuteru reports.
The filing comes after the announcement of Pokemon Ruby and Emerald, Omega Ruby and Alpha Sapphire, earlier this month. If you're hoping for this means an Emerald version remake is on the way, it's worth remembering that Nintendo trademarked Pokemon Water Blue around the same time as Fire Red and Leaf Green and that game never materialised.
Regardless of whether a new game is being developed or Nintendo is just covering their bases, Omega Ruby and Alpha Sapphire are set for worldwide release this November.
The games will feature the 3D graphics of X and Y as well as new features such as mega-evolutions. We can expect to hear a lot more about the remakes during Nintendo's online E3 events.