"Op-ed" - originally referred to the page in a newspaper that was Opposite the Editorial page. This page would not necessarily be written by someone on the newspaper's staff and would be devoted to personal comment, feature articles, etc. (it's now sometimes interpreted as "Opinion Editorial")
This page contains articles and blog pages with opinions, speculation, interpretations etc of the show. To have your article or blog included here - just add it to the "Op-Ed Pieces" category.