At TLA, I went to lunch with an author friend who said she thought that autographings were a bad idea, that they sort of reinforced "the cult of celebrity," and the whole thing should just be about the book.
Greg countered that signings were basically a way for readers to connect one-on-one with authors, that it gave them a venue to chat a few moments.
I like to see a signature and remember that literary trade books don't start out like widgets, that they're art crafted in individual passion.
To me, the touch of the creator tends to rejuvinate a copy, refreshen the magic of it.
That said, the "cult of celebrity" is definitely part of the reason that it's become so difficult to publish the kind of literary picture books (with curriculum tie-in), especially multicultural ones, that teachers and librarians appreciate most.
State librarians do anything but keep quiet from News8 Austin. A rally at the Capitol (Greg and I were there!).
To Market, To Market by author Michelle Y. Green, who also offers The 60-Second Sound Byte. Michelle's site is possibly the best author stop on the 'net. Highest recommendation.