I recently sent a family friend a wedding present. As is the case with most such occurances, I promptly got a thank you note in return... addressed to Mr. and Mrs. HIM (in other words, Mr. and Mrs. John Vee*). Now, I recently got married myself, so it's not completely irrational to assume that I would have taken his last name (which I didn't), but I still don't see how anyone expects that I could possibly have taken his first name too (Emily Post etiquette be damned). The fact that she didn't even bother to check if I'd changed my name, or how I might prefer to be addressed, shows how entrenched patriarchal norms are in modern etiquette. I have told everyone who has asked that I am keeping my last name, prefering to be addressed as Ms. HER, but that I wouldn't mind being addressed socially as Mrs. Anna Vee.
The whole idea that women have to change their last names is so last century. So why do people still automatically assume that if a woman gets married, she'll want to be addressed by her husbands first and last name? Isn't his last name "possessive" enough? I was also talking to a friend about this, and apparently they used a professional printing service to address their wedding invitations. His parents-in-law are Dr. HIM and Dr. HER, but the printers changed it to say Dr. and Mrs. HIM. The same with a close family friend who prefered to be addressed as Ms. HER because she also did not change her last name. The printer ignored this naming convention and sent off an invitation to Mr. and Mrs. HIM. Needless to say, said friend was not best pleased (this was before I got married, and is therefore not me, although as you can see by this post I would have been equally displeased). Why is the wedding industry so dead set against anything that might be outside the "normal, picture-perfect" wedding? But the wedding industry is another post entirely.
*Names changed to protect the anonymity of DH.