I don't know if this is exactly the right place to talk about this, but I thought it should go somewhere, after all, we're not the only family with a variety of religious traditions!
Thatboy and I had a big talk about religion when we started getting serious. Long before the word "marriage" came into the picture (for me). It was important for me to raise my children Jewish, and with Thatboy's Catholic upbringing, I needed to know he was on the same page. It was a dealbreaker for me.
Thatboy was more than happy to agree. He hadn't really been an adherent to Catholic tenants since he was about 16 years old. He loved the Jewish traditions he experienced with me. The only issue became Christmas.
Because I'm Jewish, we always spent Christmas with his family. (Going on 13 years now!) There was never any debate or tradeoffs, trying to squeeze in holiday celebrations with both families. So how were we going to handle it once we had a child? Especially because Thatboy didn't want to give up that special time with his family.
We discussed what it was about Christmas that he loved so. And it turned out that for him, Christmas was really about spending time with family - a decidedly nonreligious aspect. He loved the sites and sounds of Christmas, the movies, the tree, the lights. Also things that tend to draw more from a secular background. And so I had no problem agreeing to celebrate Christmas with Thatboy, his family, and our future children.
So Thatbaby gets the best of both worlds. Although you won't find a nativity scene anywhere in our home, there is a menorah and a Christmas tree. So one holiday isn't seen as "better" than the other, the "good" presents are divided between Chanukah and Christmas. Santa brings one (small) gift to Grandma's house, and fills the stockings we hang at home. All the other presents for both holidays come from us (and family and friends). Thatbaby plays with the dreidel and sings Rudolph the Red Nosed Reindeer (Santa Reindeer song) as loudly as he can.
As he gets older, we plan on sharing with him that the winter holidays mean different things to different people. Different cultures have different ways of celebrating. Daddy's family celebrates one thing, and mommy's family celebrates another, so he gets to share in both.