I will concede that the facing the people is appropriate at certain times of the Mass. Those would be the didactic (readings, etc.) parts of the Mass, while the core of the Sacrifice (Offertory through Communion), all should face in unison towards the "mystic" East.
Those who brought us Mass facing the people had an agenda contrary to Tradition and tradition. That is a verifiable fact. This whole argument is not about how one feels comfortable or not with changes, it's about what is objectively and historically and liturgically correct - and that is Mass ad Orientem. The other posters here have already made this point.
A side note...
The present practice of having the priest not be at the altar during the Liturgy of the Word arose out of the rubric in the Tridentine Pontifical Masses, where bishops would say the first part of Mass from a Throne or Faldstool off to the side. What was an exception for a special liturgy became the norm for everything (as is the case with many changes).
So, since the current rite of the Church does not do things in the old way anymore, but uses the new way, is the Mass valid?
That would really be the bottom line, wouldn't it?