Hi,
Not all domains are affected by the Christmas period, but many can be. Toys and games related domains are performing better than ever, but many others are seeing a downturn. I think we can safely assume Christmas is having an impact... people are out shopping, eating and drinking.
Not sure how January will perform... people may be strapped for cash, but on the other hand we have the January sales coming up... I expect we'll see things climbing up again shortly after New Year, and particularly towards the end of Jan.
Cheers
James