Below some recent papers of potential interest:
Hesselink, Martijn W., How to Opt into the Common European Sales Law? Brief Comments on the Commission’s Proposal for a Regulation (October 26, 2011). Amsterdam Law School Research Paper No. 2011-43; Centre for the Study of European Contract Law Working Paper Series No. 2011-15. Available at SSRN: http://ssrn.com/abstract=1950107
Hesselink, Martijn W., The General Principles of Civil Law: Their Nature, Roles and Legitimacy (September 22, 2011). Amsterdam Law School Research Paper No. 2011-35; Centre for the Study of European Contract Law Working Paper Series No. 2011-14; THE INVOLVEMENT OF EU LAW IN PRIVATE LAW RELATIONSHIPS, Dorota Leczykiewicz & Stephen Weatheril, eds., Hart Publishing, Oxford, 2012; Post-National Rulemaking Working paper No. 2011-03. Available at SSRN: http://ssrn.com/abstract=1932146
Rosenberg, Anat, Classical Contract Law, Past and Present (September 15, 2011). Available at SSRN: http://ssrn.com/abstract=1927785
Purnhagen, Kai Peter, The Architecture of Post-National European Contract Law from a Phenomenological Perspective – A Question of Institutions (September 5, 2011). Amsterdam Law School Research Paper No. 2011-25; Centre for the Study of European Contract Law Working Paper Series No. 2011-11; Post-National Rulemaking Working Paper Series No. 2011-01. Available at SSRN: http://ssrn.com/abstract=1926163