I find this very humorous. Moment Magazine asked rabbis of different denominations whether Jewish children should be allowed to sing Christmas carols. Here is my summary of the responses, by denomination (the editor explains her policy of denominational inclusion here):
Lubavitch: Here's a nice and totally unrelated story. No.
Modern Orthodox (ignore for the moment whom they chose to represent MO): No, out of respect for Christians.
Conservative: No, let's look at the history of the practice.
Reform: Only if it's for fun.
Reconstructionist: Why not?
Jewish Renewal: It's great. Here's a nice story.
Humanistic Judaism: It's part of our culture.