German government still in Bonn. When will they move (and cut costs)?

The social democratic party (SPD) is claiming a final date when the rest of the government will move from Bonn to Berlin. It sounds impossible to understand why 20 years after the fall of the wall, in the 20th year of reunification there are as many civil servants and government employees in Berlin as in Bonn. Does the German population actually know? Apparently not. The subject came up when somebody in the Bundestag had a closer look on the list of government spending.