…To my knowledge all other English-language Bishop’s Conferences that have approved the new text have also scheduled its implementation for the same Sunday (but I could be incorrect about this).
You are incorrect for Australia. From the Melbourne Archdiocese website (at
cam.org.au/evangelisation/faqs/faqs.html ):
"When do we start using the new Mass texts?
In 2011.
Australia’s Catholic Bishops have decided to implement the changes to the Mass in this way.
January 1 – Learn to sing new words
• We can sing the new translation of the… Lord Have Mercy, Gloria, Creed, Holy Holy, Acclamations and Lamb of God from January 1.
• Check the Archdiocesan Missal website below for the new and revised Mass settings. …
June 12 – Learn to say new words Pentecost Sunday
• We’re encouraged to say the new translation of the above from June 12.
• Plus the new translation of familiar responses by the people.
• The words will be on a people’s Mass card.
• We can introduce them all at once, or gradually.
November 1 – The official starting date All Saints Day
• We’re all expected to be using the revised Mass texts.
• The Altar Missal for the priest will be introduced as soon as it’s ready."