Was definitely a 767 last week when I worked it. I always notice the BA 767s when I have them because I see so few of them. Baltimore, Nassau and Calgary are the only ones I see off the top of my head.
BA will operates it's 7 remaining 767's will operate from LHR to the following destinations during the S15 schedule
Almaty - 3 x weekly
Baltimore - Daily
Calgary - Daily
Entebbe - 4 x weekly
Nassau - 5 x weekly (continues to GCM 4 x weekly)
Philadelphia - Daily (BA066/BA067 rotation from mid August)
One aircraft will be used to cover for 787 fleet
The 789 deliveries later this year will allow the final LH 767 routes to transfer over. Generally, my guess is BA has a more routes that suit the 789 than the -8. Places like Austin, Seoul and Chennai have flipped between 787 and 777 recently, so maybe the 789 can strike the right balance? Slightly "thinner" long-distance routes such as KUL, SAN and BKK could also be a good fit. These transfers could then free 788 frames to launch a new route or 2.
One of BA's managers in asia hinted that BA will operate the 787-9 on one of it's 2 x daily service to DEL. KUL is one route that I can see BA operating on 787-9's.
The 787-9's will enter service in a four class configuration. BA's flights to SAN, BKK and MAA are operated by 3 class aircraft. BA have tried offering First on these routes before and found that there was no market for the product making the introduction of the 787-9's on these routes very unlikely.
Seoul is switching from a 4 class 777 to a 3 classs 787-8 from the start of the S15 schedule. This is due to very dissappointing pax numbers in First. Most flights operate with between 0 and 2 pax in First.
BA is expected to announcing what routes will be operated by the 787-9's in the next few months. BA is also rumoured to be planning to launch two or 3 new routes in late 2015/early 2016.