Nearly four years have passed since Regulation 1/2003 entered into force on 1 May 2004, effecting a sea change in the way EU rules on anti-competitive agreements and abuse of market dominance are enforced. At the time, this change was branded by the European Commission as 'modernisation', needed in order to make more efficient use of Commission resources, particularly in the light of the impending enlargement of the EU from 15 to 25 member states.¹ In this Overview we take stock of what has been achieved since then, and explore what remains to be done before EU competition law and its enforcement mechanisms can be said to be fully fit for purpose in today's European Union.