This breathless New York times op ed piece by the author of the interesting light popular science book on Krakatoa sent me off to see if I could get any hard facts about tends in planetary earthquakes.
The table given on this page enumerates so called major earthquake counts for the years 1967 thru 2001. If you fit a linear curve to that data the trend is slightly downward. Major earthquakes are those between 7 and 8 in magnitude. Large ones are called said to be great.
The table given on this page is for the years 2000 thru 2004, it includes the recent two great earthquakes. Each step up in magnitude denotes a factor of 32 in the amount of energy released. So if you weigh all those numbers by the energy involved you get a slight trend upward.
My conclusion from this very amateur attempt to get at the facts. No. The earth is not becoming more cranky; well at least not in the seismic aspect of it’s personality.
So save your worry for something else.