I would suggest that you read Pope Benedict’s Book “The Spirit of the Liturgy”. In that book, Pope Benedict discusses the theology of the Mass and has an entire chapter on why the ad orientum position is the more theologically correct position for the priest.
Basically, the priest, when facing the same direction as us, is leading us towards the Dawn of the New Light of Christ. He is acting as the Good Shepherd, leading the flock towards the Father. We are a pilgrim Church, on a journey towards are telelogical end, and Christ, in the person of the priest is leading us. The priest, facing us, is a closed and stagnant journey.
I presume that we can all agree that the Pope’s understanding of the theology of the Mass would be superior to our own, and that we should make efforts to understand and accept instruction from him on this matter?
As an additional resource , one of the local priests here in Detroit ( who studied in Rome and was ordained to the priesthood by Pope John Paul II) discusses the book in a series of popcasts.
frjohnriccardo.libsyn.com/index.php?search=spirit+of+the+liturgy&Submit=Search