For me, right up there as the best book of the year so far is Craig Dworkin's amusing, highly detailed and exceptionally nuanced No Medium.
In No Medium, Craig Dworkin looks at works that are blank, erased, clear, or silent, writing critically and substantively about works for which there would seem to be not only nothing to see but nothing to say. Examined closely, these ostensibly contentless works of art, literature, and music point to a new understanding of media and the limits of the artistic object.
Its been noted elsewhere, I'm glad to say – a long review (which I need to read carefully) from Richard Marshall over on 3:AM and a nice mention over on THE magazine too ("What ... makes No Medium invaluable is that the author’s immersion in the field permits him to highlight the qualities distinguishing the works with a connoisseur’s appreciation."). And you can see Craig talking about, and reading from, his book in a lecture on vimeo...
I'll respond to the book – and to Marshall's review - anon (I hope!) In the meantime, take my word for it: it's a goody!