Mark Liberman has courageously returned to the nor'easter-northeaster debate, though he admits its futility: more evidence is needed, and in any case, "people are entitled to use phony dialect forms if they want." (He cites, among other evidence, some research I did on the topic in 2003, now behind a Globe paywall and outdated in any case.) I hoped he came bearing fresh results from Google's new book search toy, the Ngram Viewer, but it won't let us compare the histories of the two versions -- apparently it can't handle the internal apostrophe in nor'easter (though there are hits for noreaster).
I've been trying out the the Ngram Viewer, too, and it's easy to see its limitations. As Geoff Nunberg and other early commenters have said, it's a pretty blunt instrument, unable to handle many of the search refinements you'd need for real scholarship. But I'm having fun seeing what it says about various competing usages (not hindered by internal punctuation) that I've written about before.
For example, here's the graph for "another think coming" vs. "another thing coming," as in, "if you think you're wearing that, you've got another think coming":
Pretty scary for a traditionalist like me to see the rogue "another thing" rocketing toward respectability! But I was heartened to see that the OED entry has it as "another think," with the "thing" version labeled "arising from misapprehension of to have another think coming." Not that it will affect usage, but someday I can show it to my disbelieving grandchildren ...