[Taken from NLM]
Over at Ignatius Press' Spirit of the Liturgy page, there is a video by Fr. Joseph Fessio, S.J. where he lays out his thoughts on the Motu Proprio: Pope Benedict and the Old Mass (recorded on June 29th, 2007).
I believe that this is going to be a major step toward the genuine renewal of the Mass, and therefore the genuine renewal of the Church, which the Council so ardently desired, and I think we are going to owe a great debt to Pope Benedict for doing this."