Anyway, I've finally had a reply from Eric's department:
Thank you for your email of 29 November 2010 to our Secretary of State, the Rt Hon Eric Pickles MP regarding recent newspaper articles and comments referring to a “war on Christmas”. As I am sure you will understand the Secretary of State receives a vast amount of correspondence and cannot answer it all personally. Consequently, your letter has been forwarded to me to reply.
The Government very much recognises that Christianity has had an immense historic influence in shaping society. Churches make significant contributions in a wide range of areas, such as community development, education, social inclusion and our heritage.
Britain has a proud tradition of religious tolerance within the law. A key part of this tolerance is respect for others beliefs and religious practices and an understanding of how our own practices impact on others. The Government, therefore, takes great pride in recognising differing religious festivals throughout the year.
However, Christmas is a special time for reflection and celebration in this country, and we therefore wish you and your family a very happy Christmas and a peaceful New Year.
Which is all very interesting, but of course doesn't in any way address the main point of my letter - namely that there is no "War on Christmas" and that the three examples cited by Eric were just tabloid scare-stories that have been rebutted many, many times.
I've replied to DCLG with a Freedom of Information request asking to see any evidence that was collated or studied by the department prior to the press release being issued. A response on that is due by late January, so I'll update you all on any progress in a few weeks.