From Code To Mysticism: The Strange Ways of God and Computers

The motu proprio for the Latin mass is now out. I just found it around 2:15 PM (Rome time), that's 9:15 PM (Manila time) on July 7, as announced. I haven't found a suitable English translation yet (for those who understand Italian, go here.) but here is the gist of the document which is published in Latin.

Contrary to what some people have been expecting, the motu proprio is not about the reinstution of the Tridentine Mass which was -- I think -- never abrogated by Vatican II (although a special permission had to be obtained for it to be used). Pope Benedict XVI's motu proprio also mentions the Sacrifice of the Mass according to the Missal promulgated by the blessed John XXIII in 1962 (the revision of the Missal of Pius V) and which can be celebrated as "an extraordinary form of the Liturgy of the Church." However, it is the Missal promulgated by Paul VI which is the "ordinary expression of the lex orandi of the Catholic Church belonging to the Latin rite.

More, the motu proprio is not about the reimposition of the Latin Mass. The Pope recognizes the fact that there are still members of the Church who wish to celebrate the Mass in its more ancient form and so he is allowing them room for this according to the principles he lays out in "Summorum Pontificum". What are these rules? Here are some of them.

Any priest of the Latin rite can celebrate any of the two expressions of the Church's lex orandi -- the Missal of Paul VI or the Missal of John XXIII -- when there are no people attending (what people have started to call private masses) except during the Paschal Triduum.
For religious congregations and institutions where conventual masses as celebrated, their major superiors can decide on this account according to the proper norms.
In regard to the first two numbers, the faithful can be admitted if they do so wish it
In other places -- like parishes -- where there are groups of the faithful who request for the Latin Mass according to John XXIII's missal, they should be accomodated. The motu proprio defines the days when such masses can be celebrated. If these are not allowed, they can go to the Bishop to ask for it. If the Bishop by some reason cannot make a decision on the request, the matter is forwarded to the Commission established for such matters, the Pontifical Commission "Ecclesia Dei"
Parish priests are also to give in to the requests of other priests and the faithful for Latin Masses even for marriages and funerals.
Where the Latin Missal of John XXIII is used, the readings can be taken from the approved vernacular translation of the lectionary.

This is as far as the Latin Mass is concerned; the motu proprio mentions more so I'd suggest that you check it out first. (The document mentions also cases where a priest would like to confer blessings and celebrated other sacraments "according to more ancient rituals" (see art. 9).) The idea behind Summorum Pontificum however is clear: that those who wish to celebrate the Sacrament of the Mass in the language of the Church are to be accomodated and that no one should feel alienated from the Church because of such a desire.