George Kofler (NYU) & Ruth Mason (UConn) have published Double Taxation: A European Switch in Time?, 14 Colum. J. Eur. L. 63 (2008).  Here is the abstract:

This article considers whether the fundamental freedoms of the EC Treaty encompass an absolute requirement on the Member States to mitigate double taxation, and it concludes that such a requirement could reasonably be inferred from the goals of the fundamental freedoms and the European Court of Justice’s "double burden" jurisprudence. Notwithstanding the reasonableness of that interpretation, in the recent Kerckhaert & Morres case, the Court of Justice found that the EC Treaty permits double juridical taxation, even though double taxation distorts the Internal Market. We review the history of the Court’s relevant jurisprudence, consider alternative theories under which the Court could rule that double juridical taxation violates the EC Treaty, and compare the treatment of double state taxation in the United States by the Supreme Court under the dormant Commerce Clause.