When you really look at it, all Christian holidays that I can think of have a basis in some pagan path from the past. They've simple attempted to give pagan holidays their own slant on meaning.
I don't "celebrate" any Christian holidays per say. However, I do partake of the get togeathers, parties, and family gatherings and try to keep it in my mind the origins of the holiday at hand.
But then, I don't "celebrate" the wheel either as I don't follow a Celtic or Wiccan path.
If you feel it's wrong to celebrate....say Christmas. Don't feel bad. I'm sure no Jew or Muslim would fault you for it. And if you do want to celebrate it, go for it. It's all personal choice, what we as individuals feel comfortable with.