Want a copy free? See this contest: http://www.blog.pythonlibrary.org/2014/05/12/ebook-contest-win-a-free-copy-of-mastering-object-oriented-python/.
If you're really interested, I can sign a copy. That will double the shipping cost, so perhaps that's not the best idea.
The bad news is that the errata have started to trickle in. Some of the default serialization cases in chapter 9 aren't handled properly. The demonstrations don't exercise the defaults very well, so things happen to work for me, but don't work when generalized or pulled out of context.
Sigh.
What's important -- I guess -- is that we have a critical mass of readers who are applying the concepts and finding problems.