By now you can't have avoided hearing about the massive shift in global energy prices in particular oil.  

But why have most of our energy bills remained relatively static while the global energy markets tumble, and what way will future prices go?

The future for energy prices is anyone's guess.  As a global recession looms, and growth falters, so do energy prices.   The price drop can only last as long as there are plentiful supplies (and supply development) and a global pick up in economic activity seems far away.  Both these seem unlikely.  

The world needs more energy.  There are still literally billions of people on the planet without a secure, affordable supply of energy.  Recessions  and stagnations rarely last too long. 

In the short term, it is likely energy prices will become very volatile, bouncing around as news emerges on possible increases/decreases in economic activity and threats/gains to supply.  The US shale energy revolutions will likely be a bit loser in the short term as the extra cost of extracting these fuels will make them less competitive against overseas imports which have a much lower cost base. 

In conclusion, it is likely that energy prices will pick up (the timing is less clear).  The speed of the pick up will probably depend more of global economic growth rates and what rates are expected in the future.