In April, the Commission published its evaluation of the Ecodesign directive and (2009/125/EC) and the results were discussed at a Consultation Forum meeting of April 19, 2012. One of the conclusions of the report was:
Ex-ante impact assessments estimated that the first 12 Ecodesign Regulations will allow savings of 385TWh per year by 2020, which is close to 14% of EU 2009 electricity consumption by households. However, it is not possible to assess progress against these estimated energy savings (and consequently the 2020 policy targets) at this stage, due to data unavailability. Significant energy efficiency improvements and energy savings are possible in most categories of EuPs (Energy using products).
Given the importance of products to help meet the EU’s 2020 energy efficiency targets, especially now that the Energy Efficiency Directive has been approved, it is hoped that it will soon be able to assess the progress against the ex-ante assessments so that there is a better appreciation of true effectiveness of Ecodesign. It’s time to ask the Commission where we stand.
Energy in Demand - Sustainable Energy - Rod Janssen 
You’re very right, Rod. There surely be a gap between the ex-ante estimates and the real savings, for many reasons: assumptions that went into the ex-ante evaluation; insufficient market surveillance; macroeconomic trends, etc.
Better data on Ecodesign (be it energy savings or some sort of market monitoring system) is something some Brussels organisations have been asking for for a long and which starts to have some echo within the Commission. Only time will tell whether the interest is real.
Cheers!