and for the woman, it's probably largely about children too ...
If a non-Muslim woman marries a Muslim man, she doesn't have to convert, although even if she has no intention of converting Islam will play a large part in her life, and any children will be raised as Muslims. This is non-negotiable. In Islam, children follow their father's religion.
A Muslim man does not need to convert if he marries a non-Muslim woman; at least, not initially. Mohammed married a Christian woman and since Muslims follow and imitate the acts of Mohammed, it's fine.
I think (only think!) I've got that right?? 