Now that I seriously ponder on this... I would love it if I had on my bookshelf a well thought and designed pixel art book. Something that's a pleasure to see and read, even if you are experienced... And hopefully study from.
Three main chapters, the first dealing with what is Pixel art, and basic definitions and tutorials. The second part dealing with advanced techniques, palettes, common restrictions, and so on. And lastly, for the third part, a huge body of work from the most talented around.
Seeing such a book among all the countless digital concept art and classic drawing examples in a book store would no doubt inspire some life to the pixel art scene. (If that is what some of you would like.) And hell, last time I saw, there was an example dealing exclusively with Lego sculpture photography.