All these arguments over New Madrid arise because nobody does their physics. All these seismologists just try to jam the square hole on the round peg. :) New Madrid was just a giant natural injection well, and has done its bit. It has to come out of its stress hole to live again.
That is why I have such great hope for Oklahoma and Texas. If they really want to they can totally recreate the New Madrid events. Wouldn't that be great for tourism? Can't wait until this cold weather allows fracking again. :)