The Earth's Magnetic Field weakening in certain areas, a potential reversal coming??

 The earth's magnetic field is necessary for life as we know it. It protects us from charged particles from outer space. But we know that the field has gone through dozens of reversals - there have many times when a compass needle pointed south, instead of north! Computer simulations are starting to reveal how and why this occurs, and signs of it have been observed for the past decade or two. A new 'dent' in the earth's magnetic field around one of the well known anomalies in the South Atlantic Ocean seems to fit into the continuation weakening of the field, and follows characteristics revealed and predicted in simulations leading up to reversals. 

We'll see what happens over the next couple centuries. We are actually 'overdue' for a reversal, the last one happened around 800,000 years ago. Check out a good NOVA episode on the earth's magnetic field.