I'm on marriage number 2 right now (8 years), and we did talk about this. I didn't care if she took it or not as being into genealogy, I can see how a person would like to have a particular identity that they have always known.
However, my wife still had her name from previous husband (due to kids), so she decided to take mine anyway instead of going back to her maiden name. Neither one of us were comfortable with her keeping her ex-husbands name, even if her kids did.