I think it's likely that both British Airways and Japan Airlines--already large 747-400 operators--will end up buying the 747-8 instead of the A380-800 because both airlines have far less landing slot restrictions at their home airports (London Heathrow for British Airways and Tokyo Narita for Japan Airlines).
I get to fly a BA 747-400 in June (first time) and I'm as excited as a little school boy.