Well, I think that it would definitely pep up the LCY JFK offering. Apparently Bombardier have done a good job making the aircraft "comfortable" (quiet? higher cabin pressure?), so there are additional benefits as well as losing the fuel stop.
I'm not convinced BA are necessarily in the right frame of mind to appreciate the demand for a premium service - they seem to be concentrating on trying to get away with downgrading whilst hoping no one notices. But there's always a market somewhere or other for the very best of service. You'd think that if JFK/LCY was operated to the highest standards (the airborne equivalent of the luxury cruise, like Concorde was perceived to be) then there'd be plenty of American tourists who'd fill the seats even if the business persons didn't.
How well are Etihad doing with "The Residence" these days? I vaguely recall commentry about them being the most profitable 'seats' in the air... I've also read articles about North Americans flying Emirates to Europe to avoid AA, UA, etc. BA certainly don't want to end up being looked at as worse than flying via Dubai, no matter how cheap.
If I had the money to go Residence via the UAE I would be sorely tempted. One wonders at what point does the extra hours in the sky stop being a bore and just becomes an enjoyable self indulgence over an extended period of time. Something to be enjoyed if one is not in any particular hurry.