I was just informed that the extra appendix, the samples for the extra appendix and all the rest of the sample/exercise files for the Unleashed are now available for download on the SAMS site. When you get to the page, click on the Download link in the More Information section. Appendix C is cool because it covers most of the adapters.
Also, if you are searching for a good book on InfoPath, check out Thomas Robbins’ book. Oh, and if you want to preview a cool technology, check out a few pages of this book using the Google/Print Beta.