I can't wait for the DVD to be out! *loves Shokotan*
Several weeks ago, I went to Kinokuniya and bought some books, including this book:

It is basically a compilation of some of her early blog entries. It also has some other handy features like a glossary (so that you can know what Shoko's referencing, and some definitions of some of the...unique words she uses), stickers, an interview with her and her favorite mangaka Umezu Kazuo, a questionnaire she filled out, and some pictures of her in various costumes.
It's probably not much, but it was Shokotan-related so I had to get it.

They also had her 2nd photobook Fushigi ni Muchuu, but my dad was with me and he would definitely give doinkies some...funny looks if I bought that (and I didn't have the money for it anyway).
There's also a sequel to this book with more recent blog entries (and I assume more extras).