You know, i've seen this question many times on Y! answers and often within the media. And, to date, i still say the same thing:
1. Saying Happy Holidays is being inclusive of all faiths, and persons.
2. Saying Happy Holidays does not mean that christmas doesn't exist. It means that you should have a happy holiday for whatever holiday you celebrate.
3. Christ was not born on Christmas, he was born in March or April (dependant on what calendar you look at).
4. Putting Christ back in Christmas is perhaps the most idiotic thing i've ever heard. Not only did this holiday start as a Pagan Festivle, Christ wasn't even close to being born on this day.
If you have a problem being inclusive, perhaps you shouldn't celebrate the holiday. The spirit of christmas is to be giving, to work for harmony and peace on that one day, and do our best to have an enjoyable time in an otherwise harrowing time. Non christians still celebrate christmas. Many other's celebrate other holidays within that season and day.
I personally celebrate christmas, but moreso the traditional yule celebration. And, i still say happy holidays to whomever is concerned.
Being inclusive is very important. If you want to exclude non christians from the holiday, then you should make it illegal to sell christmas trees, ornimants, wrapping paper, ect to anyone except churches, and churches should pass such items out :) I doubt, for a single minute, that this type of action will take place; christmas means too much for retailers in our economy :) So, since it can't be that way, try and be a bit more inclusive eh :)
I twinge, yes, whenever anyone wishes me a merry christmas, and then spouts off christian bias. It offends me because i'm not a christian. I don't turn to the same person and tell them about the goddess or the harvest, so what's the point of being so rude like that :)