It is always good time to burn when airlines temporarily lower the number of required miles. Air France and KLM’s Flying Blue program does this every couple of months. They just released the list for destination that they have at 50% discount for January and February 2012.
Thing to note is that you can book these one way and these are not only for originating from Europe. All the destinations are for both directions. The discounted awards within Europe are only from the listed cities. Other awards allow the origin/destination in Europe to be in zones 1, 2, and 3, basically meaning that these awards are valid from/to anywhere in Europe.