Until the pope, the prefect for the congregation of Divine Worship or the head of Ecclesia Dei state otherwise, my pious opinion is that the following is still allowed (not mandated) for the 1962 Missal, pious opinions contrary to mine, notwithstanding which constitutes in my mind the mutual enrichment in part which Pope Benedict desired for the EF Mass:
This Pontifical Commission sees no difficulty in the celebrant and ministers joining in the singing of the plainchant Gloria and Credo together with the schola cantorum and the congregation instead of reading them privately as directed by the Ritus Servandus. This usage was already admitted by the Church a relatively short time after the publication of the 1962 Roman Missal. The same holds true, mutatis mutandis for the Missa Cantata.
b) This Pontifical Commission sees no difficulty in the entire congregation's singing of the Pater Noster in all sung Masses.
In addition to above ruling of the Pontifical Commission of 26 March 1997, the following directives were also issued:
1. If the celebration of the Divine Office precedes Mass, the Prayers at the Foot of the altar may be omitted.
2. The rites accompanying the readings from scripture may be celebrated at the sedilia.
3. The readings may be proclaimed facing the people, whether in Latin or the vernacular and the celebrant is not required to read them or the Gradual chants separately.
4. Bidding Prayers may be offered after the Oremus, immediately preceding the Offertory.
5. The "Secret" prayer may be sung aloud.
6. The celebrant may sing the entire doxology Per ipsum, whilst elevating the Host over the chalice.
7. The Pater noster may be sung by all with the celebrant.
8. The final Blessing may be sung, and afterwards the Last Gospel may be omitted.
But the greatest needed influence is the EF's mutual enrichment of the OF Roman Missal.
And as I have written before this is how it is done:
Keeping the Roman Missal in its entirety to include all the extra Eucharistic Prayers the following revisions to the Order of the Ordinary Form Mass are recommended:
(This is for a high or sung Mass):
1. The Official Introit in the EF fashion is chanted as the priests and ministers pray the traditional PATFOTA (which could be substituted with the EF's Asperges). This does not preclude an additional hymn to accompany the procession to the foot of the altar.
2. After the PATFOTA is completed, the priest ascends the to the altar with his private EF prayers, incenses it while the choir begins the Kyrie and the Gloria. The rubrics are for ad orientem as in the EF for this part of the Mass.
3. The Liturgy of the Word is from the revised lectionary and in the same way as is normal in the OF although the Gradual is explicitly stated as an option to the Responsorial Psalm.
4. Following the homily, the Credo is changed with priest at middle of altar and followed by a sober prescribed Universal Prayer.
5. The traditional offertory prayers are offered as the choir chants the Offetory Antiphon and any other motet.
6. The Prayer over the Offerings is chanted aloud.
6. The Roman Canon has a pride of place for Sundays and has the rubrics of the EF Mass included a soft-voice praying of it by the priest. The Per Ipsum is chanted in its entirety aloud with the rubrical signs of the Cross as in the EF.
7. The Rite of Holy Communion remains as is in the Ordinary Form but kneeling to be recommended as the pride of place way of receiving and on the tongue.
8. The Concluding Rites as in the Ordinary Form.