Despite the announcements, I have a feeling that this signals the beginning of the end of the joint service agreement.
Firstly – such an agreement might not be welcomed by a competitor which may look to acquire the shareholding in Qantas.
Secondly – BA has all its eggs in one basket (trans atlantic). Scrapping the agreement would reduce the reliance on this market, and allow BA more scope to open up new services to Australia and NZ.