You realise that this will open a whole new can of worms !
You will have to get used to being called plain old America and the states will have to become Counties..... eg New Englandshire, Texashire, Oregonshire etc.
Now what about the American aristocracy? There will surely be problems as the original Pilgrims, if I remember rightly, were not happy with the religious set up here and probably many (Including a couple of my ancestors who were shipped over as unpardoned criminals guilty of treason) will certainly not be able to be represented in the House of Lords.
I believe Her Majesty's representatives will be producing a CD for use in American High Schools ( Now to be called Colleges or centers of excellence ) and Elementary ( Junior) schools which will instuct the pupils on how to keep a stiff upper lip and keep emotions thoroughly under control. There will be section on keeping themselves to themselves and how to conduct polite conversations with stangers about the weather.
Oh and there will be a total ban on most American sitcoms, Jeremy Kyle will replace Jerry Springer, A Coronation Street set will be set up in Detroit and a complete North Yorshire Village will be built near Dallas so you over there can enjoy the Country Soap opera, Emmerdale.
There will be a concerted effort to sort out your housing Markets and kick starting economic growth by a progamme of house building UK style, small box like terraced houses in rows or for the more well off semi-detatched barrat houses which are even smaller than the terraces.