A trademark from Nintendo suggests that it could be considering a remake of Pokemon Emerald, named Pokemon Delta Emerald to coincide with the already-announced remakes of Pokemon Ruby and Sapphire.
Gematsu reports that the title Delta Emerald has been registered as a trademark by Nintendo in Japan, which occured on 2 May 2014 and went public on 29 May 2014.
Nintendo has already revealed that it is working on Pokemon Omega Ruby and Alpha Sapphire with a release date of November 2014.
The original Pokemon Emerald - which was an enhanced version of GBA Pokemon games Ruby and Sapphire - was released about two years after its predecessors.
While the trademark doesn't confirm this is Nintendo's intentions, if it does release Pokemon Delta Emerald slightly after Pokemon Omega Ruby and Alpha Sapphire that would be a little unfair for its devoted fanbase - who would essentially have to buy another version of the same game.
http://www.nowgamer.com/news/2416407/pokemon_delta_emerald_trademarked_by_nintendo.html