In this article George Weigel has some good information about the authoritativeness of articles that appear in L'Osservatore Romano. The gist of it is that basically, the articles and editorials in the Vatican newspaper have no special authority, but they just reflect the opinions and insights of the various writers.
However, he mentioned something that I didn't know. When an editorial is followed by three dots, that's a sign that the editorial in question came from someone of high rank in the Vatican. That doesn't make it an official church teaching, of course, but could reflect the thinking of Vatican "higher-ups".