Naming Patterns
Wow, I did not realize this would be such a hot topic!
Now as far as a husband adopting his wife's surname as his own, I have NEVER, ever seen this happen. I all my time as a researcher, historian, and genealogist, since 1992, I have not seen this phenomenon.
Now it may be the case where the children, even the males, like has been said adopt their mother's surname. So the child of, for example, José Sánchez and María Pérez, Juan Sánchez Pérez, goes by Juan Pérez more than Juan Sánchez. Thus Juan Pérez will marry and have children that become Pérez, thus abandoning their true paternal surname, Sánchez. But what I've never seen happening is that José Sánchez would adopt his wife's surname, Pérez as his own. That would be unheard of.
Traditionally, and this has been a long-standing tradition, women keep their own surname all their lives, even after marriage. To continue using the previous fictitious couple, José Sánchez and María Pérez, had they lived 175-350 years ago, María Pérez would have been María Pérez, from the cradle to the grave. But as María Cortez quite accurately pointed out, traditions indeed change. Nowadays, our María Pérez's name would change after she married. She would be called María Pérez de Sánchez, to show she's married to a Sánchez. And there was a time when this was done even in the old days, so there was a time of slowly changing traditions and naming patterns; a time when there was an overlapping of naming traditions.
