Here in the UK there has been some hype around Christmas-themed commercials. In particular, one for the John Lewis department store in which an animation involving the story of 'the bear and the hare' is underscored by a cover of keane's "somewhere only we know" by Lily Allen (interestingly singer in one of the Logic Pro 9 demo songs). This has reached #1 in the charts.
BBC radio 4 did a piece on how advertisers work music that is not necessarily Christmas themed to appear 'Christmassy', resulting in an example song (I don't feel like dancing by scissor sisters) re-worked in a Christmas theme. The result was broadcast on radio 4 and can be heard here:
http://www.bbc.co.uk/news/entertainment-arts-25324658
So, my point? Well, I am just trying to invoke a discussion on what elements constitute a Christmassy song. It seems that the BBC incorporated items such as a breathy female lead vocalist, staccato strings, bells, triangle and extended legato phrases.