High-skilled immigration (HSI) policies, and their harmonisation across member states, have been an important part of the EU's Lisbon strategy focusing on the knowledge-based economy, and the subsequent 'Europe 2020' which emphasises economic recovery. Intra-EU mobility of high-skilled workers is quite low, and member states have targeted high-skilled third-country nationals (TCNs), both through national policies and the EU's recent Blue Card scheme. However, the Blue Card Directive (adopted in 2009, transposed by June 2011), despite its scope for Unionised regulation, allows member states to decide how many high-skilled TCNs they want to admit, if any. The article argues that tensions between openness and closure to migration exist at both member state and EU level. These tensions are resolved through considerable diversity in the conditions and rights accorded to Blue Card holders across member states. Drawing on new empirical data, the article analyses first results of the transposition of the Blue Card Directive. It examines how far, in what form, and with what implications, diversity continues regarding the principle of mobility for these migrants across member states. The pattern and nature of transposition are hence important in shaping an EU-regulated liberal market in labour recruitment, and the development, or otherwise, of rights-based mobility regulation.