Re: Will you allow your child?
Like Mo3, my husband and I have a beautiful and rich relationship, alhumdulillah, and we are both better people for being in an intercultural relationship. Our children are well-behaved (most of the time) and comfortable with their identities as muslims, and it has turned out well for us. Our biggest disagreements are the same as in most marriages, money, leaving the toliet seat up (or down), not picking up clothes, etc. Over the years my in-laws and I have reached a state of "mostly" peaceful coexistence. They've been living with us for the last year (almost time for my break - yeah!!) and we have settled a lot of our differences.
I agree with Sara, though, if you are so opposed then you need to indoctrinate your children from the time they are young, in the same way that I have raised my daughters to understand that they are not permitted to marry a non-muslim. However, I feel sorry for the children of parents with this kind of narrow-minded attitude.