A while ago I wrote a post explaining why authors should work just with publishers that respect them. Peachpit, which published The Functional Art, and will launch The Truthful Art in March next year, is one of those.
Some can make you feel very uncomfortable. See the e-mail I've just received:
The first edition of that book was written by Andy Kirk. who has just told me that he won't have any control over what Packt does with his book and, because of that, he doesn't approve of a new edition. They didn't even have the courtesy of informing him before contacting other authors.
No matter what their contract says, Packt Publishing's approach —which is the approach of other publishers, unfortunately— is unethical. It may be common practice, but that doesn't make it any better. It's a practice that must die. If you're going to update somebody's book, work with that person or, at least, get all changes approved by her or him. And if you can't work with an author, you should give the rights back and create an entirely new book.
New writers, be careful.