It looks like the sample source code I downloaded from this site for this book was developed using the beta version of the Windows Phone Developer Tools.
In addition to the syndication dll mentioned on the earlier thread, until the source code is updated, you will need to read the release notes
in order to get these projects to build.
For me, it was sufficient (for the chapter 3 project) to just make the changes to WmAppManifest.xml. It looks like many of the others are already present.