DON'T SUBMIT: 1) If it adds nothing new to the discussion. Just a regurgitation of things already said. 2) If it's something that can be obtained very easily elsewhere. Already on NY Times, CNN, etc. 3) If it amounts to nothing more than a tribute. (Nothing wrong with these intrinsically, but this isn't really the forum for them.) 4) If it is overtly politically charged.
DO SUBMIT: 1) If it provides a genuinely new or original analysis of the event itself, what lessons can be learned, what lessons should have been learned, etc. 2) If it is thought provoking and has the potential to spark meaningful discussion.
I think if we followed these (or similar) guidelines then that would cut out the majority of the fluff pieces, so that anything 9/11-related that does make it through the filter will be better received.
tl;dr - Think before you post.