There's a new Pinkie TF that I've seen in Arania's site and there's this awesome story verse that seems like it's in the same vein in the Xanadu series, but it seems to be a collaborative story where all the main characters meet each other and work together. However there's no process and the Fluttershy one apparently is the ONLY GIRL that becomes a pony so far.
But other than that the stories themselves are really good and interesting.
http://www.fimfiction.net/index.php?...oup&group=1670