and is there a way to quantify it?
Every now and again (in truth, about twice a week), I check Google's latest results to see if the Wikipedia articles on 2012 and Nibiru are getting disseminated, and one thing I have noticed is that, as the date grows nearer, the number of quotes from those pages is decreasing. Either fewer people are interested in 2012 (which would be a good thing) or fewer people are interested in debunking 2012 (which would be a bad thing).
One odd effect I've noticed is that in the weeks following the spike in views on 21 May (bless you, Harold Camping), the daily number of views of Wikipedia's 2012 and Nibiru pages has fallen by at least 10% from the previous stable level prior to the Camping spike. So obviously a substantial number of viewers were in it for the Rapture, which is odd. I'm not sure whether to take the decrease as a good or a bad sign.