Recently I have had numerous discussions with people who simply put, want more Earthbound. Unfortunately however the answer for them is just as simple: there will be no new Earthbound and the chance of Mother 3 being localized is highly unlikely.
To start let us look back to March 20 of 2013, which was the day Earthbound was made available worldwide on the Virtual Console. Considering the game goes for around $300 on eBay and the fact that it became the third best selling game on the VC, it should come as no shock that fans were pleased with the release.
Following the Earthbound addition to the Virtual Console, IGN interviewed Nintendo of Ameirca President Reggie Fils-Aime. When asked if the success of Earthbound would lead to a localization of Mother 3, Reggie plainly said "I would have to say no."
Now Mother 3 can still be played in North America, as a fan of the game has translated it to English. He went as far as even saying he would allow Nintendo to use his script. Despite that offer, it seems incredibly unlikely we see the game make its way over, which is unfortunate as it would perfectly fit into the already strong 3DS library.
While the chances of Mother 3 coming over seas are slim to none, the chances of a new Earthbound altogether are, as series creator Shigesato Itoi says, "impossible." That was the response of Itoi after a fan tweeted at him asking about a potential Mother 4.
What is more important to realize is that a new game simply can not be made without Itoi. Itoi is one of the people responsible for the brilliant script that the game has, and without him the game simply wouldn't be true to the Mother series.
A fan game titled Mother 4 is currently being worked on, and while I'm sure it will be very well done, it simply wont be the same. There website anticipates a release of their project to come in the winter of 2014.
After looking through all of this information it is definitely a head-scratcher that Nintendo wont give fans more Earthbound. They are practically begging for it by supporting the old game and working on projects of their own. Unfortunately it seems like all that work will be for naught.