Two new listings have popped up on Amazon in regards to future book releases. While there aren't any images available yet, they do have a bit of information, along with release dates. Have some of that:
Rarity Takes Manehattan: A Panorama Sticker Storybook(As Whatshisgame points out, this is the same style book as Cutie Mark Quest, which was based on the episode Cutie Mark Chronicles. There is a good chance this is a season 4 episode)
Release Date: June 3, 2014
Pages: 24
My Little Pony - The Mane Event (Dress Up)Both appear to only be available on Amazon at the moment, though I'm sure they will follow the trend of everything else and hit up bookstores when they release next year.
Release Date: May 6, 2014
Pages: 24