Slightly off topic: I noticed that BA also utilizes the 777 on the LHR-JFK route. What are the chances of an equipment swap? I would hate to lose the opportunity to fly in the upper deck of the 744, especially since I have never done it (In fact, the only reason I opted to fly BA, and pay fuel surcharges, was for the chance to fly in 'the bubble').
I'm not being paranoid. It actually happened to me this past January. I was booked in the UD on Asiana's 744, ICN-MNL. When I boarded the aircraft, my seat had been changed to the front of an a330. It was a big let down.