If BA do go A380 maybe they do what Qantas did and take some A330's first to get experience of large Airbus aircraft?
To me the A330, A350, A380 option has aways seemed the most suitible for BA as larger aircraft = more preimum capacity which is their stated operating model.
A330 next year (on lease from Airbus a'la singapore air) for growth and to begin 767 replacement, option to be replaced by A350 in the future, A380 soon to take up some of the defered aircraft (to get them off of the airbus lot) has to be a sensible deal for all involved.