.."Mr & Mrs [DH's initial] [DH's surname]"?
I probably am. It doesn't matter in the scheme of things, but really, it's 2011 and I am not an appendage of my DH. It wouldn't occur to me to address anything in that way.
It's not just older people, it's our age and younger as well.
They all know my name.
If they don't want to put both initials which I agree would be a mouthful, or an envelope full, they could just put The [Surname] Family, or Mr and Mrs [Surname].
Totally hypocritically, I did take DH's surname when we got married, but at least that actually is my name. At no point did I relinquish my first name as well.
Grrr.