Americans have always prided themselves on being a great melting pot. We have a plethora of traditions, religious beliefs, and cultural leanings that are equally "American" and thereby protected by our Constitution. I have to wonder whether the advocates of the "Happy Holidays" greeting, as well as the Holiday Tree, etc., are actually doing a disservice to political correctness. Here's what I mean.
When I was in graduate school, one of my Jewish professors wished us a Happy Easter. We didn't gasp or correct him or ask him to be more politically correct. Rather, we thanked him and wished him a Happy Passover.
The lesson I take away from moments like these is that true political correctness promotes inclusion, rather than exclusion or trivializing neutrality. I'm a Christian, and I don't celebrate the holidays of non-Christian faiths. Yet, when my Jewish friend wishes me a Merry Christmas, I have no qualms about wishing him a Happy Hanukkah. If somebody wants to put up a Christmas tree in a public forum, I say great. Just don't patronize us by calling it anything other than a Christmas tree. Moreover, I think we should also welcome the inclusion of a menorah, and any other religious symbol for that matter.
So sure, Happy Holidays! But, make sure that means inclusion.