How about locking duplicate threads the instant they pop up. That way posters still get their soapbox without fragmenting discussion?
That presumes we know it's one of many. When news stories are breaking, the actual number of threads telling us it's breaking can be daunting. If the first few hit page 2 we may not see them. We do try to merge threads as soon as we see them when the post count is relatively low on at least one of them. What happens then is an OP will just redo his original thread so now we have a duplicate of a duplicate,
“Never argue with an idiot. They will only bring you down to their level and beat you with experience.” MB Rule # 1