The case is ZAGG, Inc. v. Catanach (E.D. Pa. Sept. 27, 2012). The full opinion is available as a pdf. I will publish an extended excerpt later today.
Though this is a federal court in Philadelphia, it applied Utah defamation law.
[T]his case is a potent reminder that we as bloggers are betting our house with each blog post we make – and where we disseminate “negative” information that gores someone’s ox, the wounded ox just might gore us back. It’s one of the reasons why, after 2,000+ blog posts over nearly 8 years, my fingers still tremble a bit when I hit “publish” on a blog post that trashes a real live company or person. You as the readers tend to enjoy the bloodsport, but it’s only fun and games until someone gets sued.