Christmas & NYE is still a 744.
This route is the reason I am in BAEC. Nobody else operates LON->SAN direct. Before the direct service I used UA via SFO. Also went through a period of flying to LAX on VS and catching the train down, but these days I want the comfort of a direct service. I do wish we had twice daily though. There is a blurb somewhere on the FIS facility in SAN being expanded. Right now they can't handle more than two wide-bodies at a time...