It's been a long time coming but BA and Qatar Airways have announced the launch of a joint-business from 30 October 2016:
A long overdue challenge to EK/QF's eastbound domination out of the UK regions, and shores up both BA and QR positions at LHR with or without R3.
Wonder if BA will now ditch its last surviving service to Australia (the daily BA15 to SIN/SYD) in favour of routing its Australian traffic via Doha on QR metal instead.