I've been sating my appetite for more ponies since season 2 ended with stuff like these:
http://www.youtube.com/watch?v=Sob1t-iUCmE - About two characters from the show who the fans have decided are roommates. They've each only appeared twice, very briefly, but they're quite popular. The gray one is unofficially named Octavia and is a cellist in canon, seen with a serious expression on her face when she plays. The white and blue one is unofficially named Vinyl Scratch, and was unofficially called DJ Pon-3 as her stage name, until Hasbro made her fan-picked stage name canon recently due to her popularity. We'll see when they release the toy this fall, whether the notes that come with it state her "real" name as well or only her stage name, I guess. As I said, DJ Pon-3 and Octavia have no lines on the show, but the impressions of Twilight Sparkle, Rainbow Dash, Pinkie Pie and Discord are spot on. It's amazing how well the fans can do this stuff.
http://www.youtube.com/watch?v=hP8Wmw0UpBg - A video personals ad from Twilight. Again the Twilight impression is spot on, and Spike the dragon's voice is close.
http://www.youtube.com/watch?v=_U0QDt8wiCs - About a minor background pony and a fan favorite. The brown earth pony is unofficially named Dr. Whooves, due to his hourglass cutie mark and supposedly his resemblance to one of the Doctors (I don't know, I don't watch the show). He has one speaking line in the show, and he does not have a British accent, but in this video he does for humorous effect.
The pegasus's name is in flux. She has been known in the fandom as "Derpy Hooves" since the beginning of the series due to appearing in one scene with eyes pointed in different directions, and as the show went on it became apparent that she is clumsy and airheaded. She has several lines in one episode, and Rainbow Dash called her by name as "Derpy", and she had a dramatic lisp. Most people loved this, but some crybabies decided that the word "derpy" was "OFFENSIVE OMG" to developmentally disabled people, and Hasbro and/or The Hub (the station where it's aired), not wanting to cause trouble, redid the beginning of the episode, removing her name, changing her voice, and making her less crosseyed, much to the dismay of fans. Originally they wanted to call her "Ditsy Do" but they changed it last-minute to Derpy, and as far as anyone knows they may change it back. The show's crew still call her Derpy though. There was a big "Save Derpy" movement when that happened, and although she continues to appear in the show with her normal personality and misaligned eyes, she hasn't had a speaking part since. This controversy was what first drew me to MLP:FiM. Anyway, both the original and modified versions of the episode are available in full on YouTube, so you can compare for yourself. It's called "The Last Roundup". I haven't listened to the modified version much, but I think Derpy's voice, in this video with Dr. Whooves, is close to her new voice on the show.
EDIT: Also,
http://www.youtube.com/watch?v=sYf64O-tsy4 - Just some silly walk cycles with pretty colors and chiptune polka music.
