Jet Setter 01,
The initial website and the 'rumours' from within state that ALL recruiting for this financial year will be to the Short Haul fleets. The 320 fleet at LHR is expanding slightly into next year and the LGW 737 fleet is remaining static.
The internal pilots 'wish list', Priam, to move between fleets was published for input this week. I would suspect that the company is being proactive about the wish for many to move across to the expanding 777 fleet this year. Bear in mind that you will be initially type frozen for 5 years upon entry at which point you may bid but BA will only look at your bid if desperate, something that won't be happening for a while!
If you get in, in all probability, expect the 320 at LHR.