I'm not biting. From looking through the various logos Google has had in the past, it's pretty eclectic, but all of them are for purposes/holidays that can be considered celebratory or lighthearted (including 4th of July). None of them are for holidays that would be considered overly serious, and I think with good reason. Someone is bound to get annoyed if Google starts doing their cutesy, pastel-colored cartoon logos for holidays that are meant for reflection/rememberance (i.e. Memorial Day).