Episcopal conferences play a role:
388. Those adaptations spoken of below that necessitate a wider degree of coordination are to be decided, in accord with the norm of law, in the Conference of Bishops.
A rather nice candy-coating of current translation dynamics:
389. It is the competence, in the first place, of the Conferences of Bishops to prepare and approve an edition of this Roman Missal in the authorized vernacular languages, so that, once their decisions have been accorded the recognitio of the Apostolic See, the edition may be used in the regions to which it pertains.[Cf. Canon Law 838 §3]The Roman Missal, whether in Latin or in legitimately approved vernacular translations, is to be published in its entirety.
Well, some countries are permitted to publish partially. This is a US rule. A few other countries. Not everybody.
390. It is for the Conferences of Bishops to formulate the adaptations indicated in this General Instruction and in the Order of Mass and, once their decisions have been accorded the recognitio of the Apostolic See, to introduce them into the Missal itself. They are such as these:
• the gestures and bodily posture of the faithful (cf. no. 43);
• the gestures of veneration toward the altar and the Book of the Gospels (cf. no. 273);
• the texts of the chants at the Entrance, at the Presentation of the Gifts, and at Communion (cf. nos. 48, 74, 87);
• the readings from Sacred Scripture to be used in special circumstances (cf. no. 362);
• the form of the gesture of peace (cf. no. 82);
• the manner of receiving Holy Communion (cf. nos. 160, 283);
• the materials for the altar and sacred furnishings, especially the sacred vessels, and also the materials, form, and color of the liturgical vestments (cf. nos. 301, 326, 329, 339, 342-346).
It shall be permissible for Directories or pastoral Instructions that the Conferences of Bishops judge useful to be included, with the prior recognitio of the Apostolic See, in the Roman Missal at an appropriate place.
Thoughts on what you see in your parish, diocese, or nation in this list, which, by the way, is not exhaustive.
Catholic Sensibility 