Joined Cases C-182/03 and C-217/03: Judgment of the Court (Second Chamber) of 22 June 2006 — Kingdom of Belgium v Commission of the European Communities (State aid — Existing aid regime — Tax regime for coordination centres established in Belgium — Application by an association — Admissibility — Commission Decision that the regime does not constitute aid — Change in the Commission's appraisal — Article 87(1) EC — Protection of legitimate expectations — General principle of equal treatment)