Yes, there are already at least two specialist works on the Rome I Regulation, but that has not stopped the UK’s Ministry of Justice from producing guidance on the main provisions anyway. Here’s their reasoning:
The purpose of this guidance is to provide a brief summary of the most important provisions in the Regulation. The Regulation is a substantial and complex instrument in a technical area of law and the contents of this guidance is only intended to be a brief outline of some of the most significant provisions. This outline is not comprehensive in nature. For a more comprehensive view of the Regulation, and the many issues to which it will inevitably give rise to, reference should be made to specialist literature on private international law.
The Regulation provides uniform choice of law rules applicable in contractual obligations. These rules will enable courts throughout the European Union to select the national laws appropriate for the determination of proceedings where the case has a cross-border dimension. Issues concerning the interpretation of the rules in the Regulation can only be conclusively resolved by the European Court of Justice. As a result, any interpretative indications given in this guidance should not be regarded as conclusive in this sense.
So, brief, incomplete and (once the European Court has started ‘interpreting’) probably wrong. But still, it’s worth a read. Download the PDF here.