A lot of people are getting upset over this "Happy Holidays". Stores, in the interest of diversity, say "Happy Holidays" instead of "Merry Christmas". This way they don't offend Muslims, Jews, aetheists, agnostics, Hindu, Kwanza-nites or dogs. Christians are upset, because it means taking Christ out of Christ-mas.
First I believe stores should be willing to step out and take a risk. If you're buying things that are obviously Christmas-oriented (Christmas wrapping paper, Christmas lights, Christmas cards, etc), they could guess. If you're buying stuff that says Hannukah, they should wish you Happy Hannukah (I've said that to friends who were Jewish). If you're buying something that says Happy Birthday, they should mention that too.
But I have an answer to the indecisive who say "Happy Holidays!". Simply turn and ask them "What holiday?" or "Which holiday?" If they truly want the holiday to be happy, they should tell you which one, or what day it is. I'm not sure when Hannukah is, but I want to have a happy one. And Kwanza doesn't hold special meaning for me (I probably misspelled it), but I'm cherish the day (as I do other days). Besides, I could take the day off and relax with family and friends. I just need to know which holiday is supposed to be happy.
So next time the Wal-Mart greeter tells you "Happy Holidays", ask them "which Holiday?"