I took Dh's name when we married because my father never had any particular attachment to his surname. Indeed, when he married my mum, he suggested they take her (four letter English) name instead of his (twelve letter German monstrosity). She refused, but since it didn't mean that much to him, I didn't feel so bad about changing it.
And while I'd like to say I would always keep the same last name as my children, it is a well-known name in this area. I would keep it in the event of my husband's death, perhaps, but probably not in divorce. As it stands, people often ask me about relations to X or Y, and while I kind of know how the family tree works, it is often easier for me to say I married into the family and I am not sure how closely related we are to X or Y. In the event of divorce, I don't know that I would want to even try to answer those questions.
If there would not be children in a marriage, then I would not even consider changing my name. I never felt any particular need to share a name with my partner, but I definitely wanted the same surname as my children (and then it would have been a battle over which surname to give the children because I do not believe in automatically naming children after the father).