It looks like My Little Pony has an annual book, and the 2013 one is listed for pre-order on the UK Version of Amazon, with an August release date. It is unknown at this point if it will be g4 focused, but considering they haven't released one in 3 years, I'm going to go ahead and assume it is. Looking at the list on amazon, they don't seem to be the most popular things in the old gen fandom. Hopefully they do something cool for us new folks to get us into it! Find the Derpy on every page maybe?! The Great and Powerful pop up book? Who knows!
Thanks to Industrial Breeze for the heads up!