Summary: book description and some marketing information. For more useful information you can go to the Pragmatic Programmer's page for the book which has a link to download the code, an errata list, a table of contents and links to two excerpts from the book. You can also buy the PDF version or both the PDF and paper versions on the Pragmatic site.
In conclusion this is a great book if you are currently toying with using TextMate as your Mac OS X editor. It is a good book and second manual if you are already a heavy TextMate user and want to know how to get the best out of the programmability of TextMate. So all TextMate users should consider this book a must buy. This is one hunk of extra documentation for TextMate, at only 182 pages it isn't a large book but it is full of information. For your money you'll have an immediately useful book that will take you months to digest.