Holiday theming shows users that a website is active and in step with the experiences of the user. We don't do much holiday theming on the Vineyard Gazette website; we do for 4th of July and Christmas. It's not a cheesy clipart graphic, or full logo redesign like Google does. It's just subtle coloring in the navigation. I reused the theming for the Christmas page and the voters' guide.
Subtle coloring of a newspaper website.