I have an interesting take on this since I am a Catholic who used to celebrate Hanukah.

What the heck are you talking about?

My next door neighboors used to be Jewish (they have since moved away). As a courtesy, they would invite us over for ethnic foods, and to take part in their religious customs as an observation. As such, I have a great respect for Judiasm. I used to celebrate a Jewish holiday, not for the symbolism, but for the people, and the fun of being welcomed into another culture. Not to get all sappy, but holidays are about being with friends, and celebrating the important things in life, whether for you they be religious or not. Having spent religious holidays with people not in your own religion is an awesome experience.

So all I ask is that if some Jewish (or Muslim, or Wiccan, or other non-Christian) observer gets wished a Merry Christmas, please respond:

And a Happy Hanukah to you too

No one's holiday is right or wrong. Wish them a form of blessing in your own way. Words, after all, have more in context than in content.