They are not saying much except that Andrew Breitbart has passed away of natural causes early this morning in Los Angeles. I imagine more will be posted on the news sites as the story develops. He will be missed, we have lost a truly outstanding American Patriot.
Also see: http://www.foxnews.com/politics/2012/03/01/andrew-breitbart-dies-natural-causes-website-reports/, (Update at about 11:15: The story at Fox has been updated, since I first saw it, to say that Breitbart collapsed while walking near his home around midnight. It goes on to indicate that he had previous heart problems but does not go as far as stating that heart problems caused his death.)