Earthquake prediction or forecasting is often looked upon as being akin to astrology, and recent events around here would suggest that is a good analogy.
Many countries undertake scientific work to investigate earthquake forecasting, and rigorous testing is being carried out as well. The Southern California Earthquake Center organised a competition where teams of scientists were invited to forecast the probability of an earthquake of magnitude 4.95 or higher, during the period 1 January 2006 and 31 December 2010, over an area encompassing California and adjacent areas.
Once the time period was up forecasts were compared with actual events and it was found that some teams had had some success in forecasting earthquakes. These forecasts were not like bus timetables giving an exact place and time, they were much more generalised. A report on the study and the results are on sciencedaily.com here.
The Southern California Earthquake Center website is here.