There's a list of episodes that were made, and most of them match the episodes that were released, which means this entire list is probably 100% correct. I dunno for sure, but we can only presume. In this blog, I'm going to give you my theory of episodes 14-26, who stars in them, and what it's about. I know for a fact I'm not going to get ALL of them right, but a few of them I'm almost completely sure about. I'm going to make the list, and we'll see if I'm right when the second half comes out.
Episode 14 - Canterlot Boutique: Rarity is thinking about expanding her shop to Canterlot, but before she can open it, she needs to hire somepony to run the Canterlot shop, so she looks around Canterlot for somepony to match her exact abilities.
Episode 15 - Scare-Master: Fluttershy gets too scared to leave her house for the Nightmare Night Festival, thinking everypony is going to scare her all night, so her friends try to help her conquer her fear. Fluttershy then finds out the only way for her to not be scared is to be scarier than everypony in town.
Episode 16 - Rarity Investigates: Rarity finds out that Spike is no longer interested in her, so she investigates to find out the source of it.
Episode 17 - Made in Manehatten: The castle's map calls Applejack to Manehatten, so she and the Cutie Mark Crusaders head over to Manehatten to visit old family members while they visit. As the crusaders visit Babs to see her with her new cutie mark, they find out her destiny is not what they expected to be. Meanwhile, Applejack is trying to find out why the map called her to Manehatten when she doesn't even find any friendship problems for her to solve.
Episode 18 - Brotherhooves Social: Twilight Sparkle invites her brother Shining Armor to Ponyville so they could spend time together, but their time together runs short when Shining meets Big McIntosh and hangs out with him more than her. Twilight gets jealous over their bond, so Twilight goes into extreme measures to get her brother's attention again.
OR...
The Brotherhooves Social is being played at Sweet Apple Acres, and Twilight Sparkle and Applejack begin to fight for whose brother is better.
Episode 19 - Crusaders of the Lost Mark: Apple Bloom throws in the towel and decides to quit the Cutie Mark Crusaders, so Scootaloo and Sweetie Belle try everything they could to persuade her to come back.
Episode 20 - The One Where Pinkie Knows: Fluttershy starts to have an issue with one of her animals, and she has no idea what the problem is, but when she finds out that Pinkie Pie knows of the animal's problem, the two of them journey to Zecora's for the cure; however, Zecora is missing one ingredient for the cure, so the three of them journey to Zecora's homeland to find the missing ingredient. Little did they know Pinkie was familiar with the area.
Episode 21 - Hearthbreakers: The friendship map sends Pinkie Pie alone back to her rock farm during Hearth's Warming, only to find out that one of Pinkie's sisters, Marble Pie, didn't come home for Hearth's Warming, so Pinkie, and her sisters Limestone and Maud journey out to find her.
Episode 22 - What About Discord?: When Rainbow Dash throws a party after officially becoming a part of the Wonderbolts flying squad, Discord starts to feel left out knowing he was the only one not invited, so he throws his own party, hoping that his party would be more attractive to the ponies than her's.
Episode 23 - The Hooffields and McColts: Spike finds out that an ultimate gem that represents the most noble dragon has been found. Excited because he's been waiting his whole life for this moment, he journeys to McIntosh Hills to locate the gem, unaware that hundreds of other dragons have the same idea, including some dragons Spike has known in his past.
Episode 24 - The Mane Attraction: A new pony arrives in town with a deep-dark secret, and only the Cutie Mark Crusaders can help her with it, as the three fillies share something in common with her.
Episode 25 and 26 - The Cutie Remark Parts 1 and 2: Starlight Glimmer returns to Ponyville and it becomes her next target for taking over. While the Mane Six try all they could to stop her, it may turn out that anypony with a cutie mark is unable to stop her.
I really hope you like these ideas, because I sure do! I have no idea that these are right, but I hope they are. If it's the highly unlikely possibility that these are right, just so we're clear, it wouldn't be the first time DHX and I shared the same ideas. I DO NOT work for them, so I have no clue what's going to happen!
If you want, you can give me your episode ideas too! I'd be most interesting! :D