Well it was just announced that November Season 3 will be starting. Season 3 has 13 episodes. Megan McCarthy,Cindy Morrow,MA Larson, and Dave Polski are going to be the writers for the season.McCarthy will be the showrunner for the season.
These are the episodes each writer has written in the series.
Megan McCarthy:Dragonshy,Call of the Cutie, Green isn't your Color,Party of One,Lesson Zero,Sweet and Elite,Hearts and Hooves Day, and A Canterlot Wedding part 1 and 2.
Cindy Morrow:Griffon the Brushoff,Winter Wrap Up,The Show Stoppers,Owl's Well and Ends Well,Sisterhooves Social,Family Appreciation Day, Read it and Weep, and Hurricane Fluttershy.
MA Larson:Swarm of the Century,Sonic Rainboom,The Cutie Mark Chronicles,The Return of Harmony part 1 and 2,Luna Eclipsed,Secret of my Excess,The Super Speedy Cider Squeezy 6000, It's About Time,Ponyville Confidential.
Dave Polsky:Feeling Pinkie Keen and Over a Barrel.
San Diego Comic Con 2012 had a panel and they showed some Season 3 stuff if you want to look for that. Other then that they have been quiet about Season 3.