Aww what a great thread [I know, I'm reviving it again]. In my defense I fell off the wagon back in July and I'm just now catching up with stuff.
I have some thoughts on this subject and a bit of a logical/fluid dynamic going on with language in our home. We are a GeorgiaGirl, YorkshireBoy mixed household, and I also have Western/Southwestern American [mostly Native American] influences from my Dad's family. I try to be very practical about language because I know mine will/has changed, where DHs most likely will not.
I generally go with the word that has fewer syllables, for example:
blinker not indicator,
flat not apartment,
pants not trousers [but then I use 'briefs' instead of the other american 'underwear'],
Then there are words that have the same number of syllables, so I go with what rolls off the tongue easier, like:
buggy not trolly
windshield not windscreen
jumper not sweater
lead not leash
pavement not sidewalk
Then there are a few I just like:
holiday not vacation
zed instead of zee
and you're going to have to pry 'mah frahd gre[a]en toMAters' out of my cold dead hands...
I am a stay at home mother, so I often find myself using more 'Britishisms' when we haven't gone out much, or i haven't ventured outside the 'hood. We live in a very Korean area, with some Latinos, so we very rarely hear Southern accents on our outings, and the children have mixed accents. My hubby has influenced what we say a lot! When he leaves to go to work on Monday, my accent is already halfway there, lol. I don't do it on purpose, the WAY I say things, but I do pick in choose which British words I use.
Also, I don't think it's fair the way folks pick on Madonna. Almost any American you ask would expect a person to lose their 'foreign' accent after living here a while. Why wouldn't others? She's lived in the UK for a long time, hasn't she? I've never thought it was funny or tease-worthy that the way she speaks has morphed.