It is, I'm afraid - we are already stamping January as a due date in library books, and classes in school will already be learning about Christmas. There's a small display upstairs of children's books and media items - to find more, just search for Christmas in SUPrimo (probably best to use "Advanced Search" and "keywords anywhere").
Some other resources that I have come across that might help are:
Richard and Judy’s Children's Christmas Book Club 2011 (via Booktrust).
Christmas resources for primary schools - activities linked to Christmas around the world, from webanywhere.
3 links for creating a festive classroom - also from webanywhere.
TES teaching resources.