According to Bowker, publishers in the United States, United Kingdom, Canada,
Australia and New Zealand released 375,000 new titles and editions in 2004. [Bowker, October 12, 2005]
You know... I would have thought it would have been more. There is bad news though. Although this is an increase overall, there has been a decline in science and technology titles. It's only the "soft" topics like fiction, religion and children's books that are actually increasing. I was going to say something snarky about the U.S. being the biggest part of the overall growth as usual, but, given that last point, I'll let them take all the credit.
C'mon people! Write and sell and buy more smarty-pants books! C'mon!