What I like about Think Stats is that it is direct and to the point. It includes a case study that runs through the book and works on data available online. It provides a great starting point for exploring once you see how the given examples work. Each chapter has a handful of exercises that can get you started if you aren't sure what to do next. Downey has an easy style of writing and finds the fine line between enough information and too many details. That said, this book might be a bit thin if you don't have any experience with statistics or have access to a mentor.
Keeping in mind the that the book is a focused overview, it certainly supports the programmer who is looking for hands-on examples but I believe it also is useful for the non-programmer that needs a quick understanding of the core concepts. They may not be able to do the calculations but they will be able to participate in a conversation.
As it's concise and has active examples, the book would be a great supporting text for a course that requires assumes some statistics experience but doesn't need the overhead of a full-blown stats book. As I have mentioned in other reviews, this book is a good addition to the O'Reilly collection of books on data mining - Segaran's Programming Collective Intelligence, Russell's Mining the Social Web, and Janert's Data Analysis with Open Source Tools.
Full information: Think Stats by Alln B. Downey, O'Reilly Media, Inc.