Rorate Caeli carries the piece by Damian Thompson - below, but adds the words of the Holy Father in the accompanying letter to Summorum Pontificum. I know I bore people by saying this document is much more than about the TLM, but it is.
Looking back over the past, to the divisions which in the course of the centuries have rent the Body of Christ, one continually has the impression that, at critical moments when divisions were coming about, not enough was done by the Church’s leaders to maintain or regain reconciliation and unity. One has the impression that omissions on the part of the Church have had their share of blame for the fact that these divisions were able to harden. This glance at the past imposes an obligation on us today: to make every effort to unable for all those who truly desire unity to remain in that unity or to attain it anew. I think of a sentence in the Second Letter to the Corinthians, where Paul writes: "Our mouth is open to you, Corinthians; our heart is wide. You are not restricted by us, but you are restricted in your own affections. In return … widen your hearts also!" (2 Cor 6:11-13). Paul was certainly speaking in another context, but his exhortation can and must touch us too, precisely on this subject. Let us generously open our hearts and make room for everything that the faith itself allows.