Nintendo has filed a trademark for "Delta Emerald," leading to speculation that the third and final third-generation Pocket Monsters title will be getting a remake, in addition to the previously announced Omega Ruby and Alpha Sapphire.
The trademark was filed earlier this month in Japan, but seeing as how Nintendo has yet to announce anything official regarding yet another Pokémon remake, we can't go jumping to conclusions just yet.
It's worth noting that we never did get a Pokémon Crystal remake for DS, after both HeartGold and SoulSilver were released for Nintendo's dual-screen handheld. That, however, doesn't preclude the Big N from doing it this time with Pokémon Emerald.
With E3 right around the corner, there's a good chance we'll hear more, so stay tuned.