Of all the anime I've watched (Granted I'm no expert not by a long shot) I have frequently seen specials with christmas themes and many shows surrounding valentine's day (a day when girls give guys chocolate in japan a little different from the holiday here) Those are pretty much the only 2 holidays I've seen beyond summer vacation type stuff. Honestly I don't see these two themes out of the realm of possiblity, if they honestly want to do filler for so long.

Originally posted by: LobsterMagnet
Since halloween, Thanksgiving, and Christmas are in filler territory, they could do a special for each one w00t for corny holiday specials...
I don't know before this summer I would agree with you, but after seeing both tiger mizuki and the legendary stupid brothers at the same time I think just about anything goes. Although do they even celibrate those holidays in japan?
Also again not an expert on Japanese culture. But I believe in Japan they celebrate Christmas, Valentine's Day, White Day (May 14th exactly one month after valentine's day men are suppose to return the favor and give chocolate to girls, traditionally white chocolate which is why it is called White Day) and um.... Girl's Day in March? crude I'm forgeting when Girl's Day is. But those are the holidays I know. Of course they don't celebrate thanksgiving and Halloween from what I know is an exclusively US holiday (best one to I LOVE halloween [img]i/expressions/face-icon-small-smile.gif[/img] )