The story's been already completed, and caught the imaginations of its readers so strongly it inspired many other authors to write http://www.equestriadaily.com/2011/06/fallout-equestria-side-stories.html for it, two of which have become remarkable enough to deserve extra attention: http://www.equestriadaily.com/2011/08/fallout-equestria-project-horizons.html (http://tvtropes.org/pmwiki/pmwiki.php/Fanfic/FalloutEquestriaProjectHorizons), which takes place in the even darker and edgier Hoofington area, andhttp://www.equestriadaily.com/2011/10/story-fallout-equestria-pink-eyes.html (http://tvtropes.org/pmwiki/pmwiki.php/Fanfic/FalloutEquestriaPinkEyes), which is told from the perspective of an eternally 6-year-old ghoul as she wonders into the setting for the first time. Oh, and it's got http://www.google.es/search?q=fallout+equestria&hl=es&client=firefox-a&rls=org.mozilla:es-ES:official&prmd=imvns&source=lnms&tbm=isch&ei=syL_TtzfPI-v8QP2wZ2yAQ&sa=X&oi=mode_link&ct=mode&cd=2&ved=0CBYQ_AUoAQ&biw=1920&bih=921 (just ask Google Image Search), audiobooks, and even an animated cartoon (look for the latter two on the first link of the page)
For anyone discovering these stories for the first time, be warned. They are http://images.cheezburger.com/completestore/2011/12/21/4f38956a-b95c-4c76-b60a-0451690f7b45.png. And http://tvtropes.org/pmwiki/pmwiki.php/Main/JustOneMoreLevel.