Yes, Fairly Grim Tales is now a book, available at Amazon and Barnes & Noble! Amazon offers a look inside but the preview often ends before the end of the story. So for a look at one start to finish, I've posted The Beautiful Swan & the Silly Goose here to give you an idea of the fun you're in for if (I mean when) you buy the book. Not to mention the hilarious illustrations by Tom Hachtman that come with it.
Fairly Grim Tales also now has its own Facebook page that you could like (what's not to?).