wow, nine pages on this thread!
In Germany, where I come from, they did away with 'Fraulein' back in the seventies, at least officially, though it took some time to be universally adopted. (Which it has been for some time now, so addressing a young German woman as 'Fraulein' is certainly a faux pas!)
For as long as I have lived in the UK I have used 'Ms' - single, married, divorced, always Ms. Why should anyone infer my marital status from my title? It's nobody's business.
And don't get me started on women being addressed by their husbands' first name plus surname! That is a throwback to the dark ages.
Also, it took me a long time to get used to school kids calling female teachers Miss. That seems extremely oldfashioned! If they call male teachers 'Sir', surely the female equivalent would be 'Madam'??