The title appealed to me a year or so ago, and I found the first chapter online somewhere. It was promising, although very... American.
There is definitely a cultural difference in religious language and devotional style, and sometimes that's irritating. But non the less I found it good and inspiring.
However, I also read some criticism, basically saying Warren takes his liberties in quoting scripture.
Plus, I'm suspicious about christians that become celebrities and millionaires by doing what God has commanded everyone to do, and without payment: spread His word, teach, heal, and so on. There is too much money making involved here.
However, there's nothing wrong with publishing books in order to teach christians about the word in general, but the book where we are really supposed to learn our purpose is the Bible, and if all of The Purpose Driven Life is like the Day 1 chapter it's not exactly a Bible study, more like a collection of inspirational texts.
So I agree with searcher7, read it with discernment. You shold actually always do that, so that hint is a bit redundant.