I think the banner is a bit large. You can't see any of the content on the site without scrolling down (you have a tall banner and then those scrolling images).

The only thing I really see that is Christmassy on the site is the banner. I like the blue and red colors, but since you can't see the banner when you finally scroll down to the forums, there isn't really a tie-in to Christmas any longer.

You wouldn't happen to know how to reduce the size of that animated gif in the header without losing the animation?

Try a google search. I remember there are a couple where you can upload the gif and give them the new dimensions.