Veterans Day is today in the United States, in the United Kingdom, it is Remembrance Day. You can see very special logos from Google, Bing, Ask, AOL, and others for the special day.
Unfortunately, Yahoo doesn't have a special logo for the day. They do have an animated logo with a balloon but nothing specific to Veterans Day from what I can tell. Dogpile has not posted their logo yet, but I assume they will soon, since they have always posted a logo for the day.
Forum discussion at Google Web Search Help.