In the mad scramble to get this book to press, it seems to be a whirlwind of proofing, fonts, subtle errors in figures, and a ton of other last-minute minutiae.
The first few chapters of Pro Drupal Development have now entered the final phase, "Production". This means we're looking at copy-ready text exactly as it will appear in the printed book and just trying to find errors.
We're in the midst of a final push to get the Drupal book done. Writing, revising, getting feedback, revising again. It's nice that Drupal 5 is out so we have a definite codebase to work with!