In response to the commenter who asked if there was going to be a beta book.
UPDATE: Clearly I should ask about these things before I post. Jim Minatel from Wrox added the following in comments:
There will be a PDF about six weeks after the print book, meaning end of March or thereabouts. There will also be an Amazon Kindle version, eventually.
Also after 6 weeks, the book will be available via Wrox's online subscription service: http://wrox.books24x7.com.
It won't be on Safari, apparently Wrox books aren't part of the deal there (which I actually was kind of wondering about). Meaning I still haven't placed a book there)
I now return you to my earlier, ill-informed, blather...
Unfortunately, I'm pretty sure the answer is no. Not only doesn't Wrox tend to do that kind of thing, at this point, the book is do to go to press in about two weeks, so the amount of time to get feedback would be sharply limited.
At one point, I was told that sample chapters would be available online before release, but I don't have any information on whether there will be an e-book available. I don't think there will be a direct purchase of a PDF, but it seems as though Wiley just joined the Safari book store, and the book might be available there. I'll try and find out for sure this week.