The EU Commission's Final Report on its "Study on the Economic impact of open source software on innovation and the competitiveness of the Information and Communication Technologies (ICT) sector in the EU" is now available on its policy documents, publications and studies page as a PDF.
I thought you'd be interested in the conclusion regarding total cost of ownership. Is it true that switching to Open Source will cost you more than staying with Windows, as Microsoft's "Get the Facts" page claims? No. The study found:
EU Commission Study Finds You'll Save Money Switching to FOSS.