The "press" has been deteriorating into opinion and spin, so I don't think we'll notice much difference between the "opinion blogposts" and "the press." There won't be any single event that future generations could say "here is where the press died" any more than one can definatively state that "this was the event where the Roman Empire fell."

True that, but the worth of printed word was varying like that for eternity. But at least there always was a score of quality publications which try to separate opinion, reporting and analytics into separate columns.