Fr. Z , hardly a raving liberal, has found the answer to the question about the 3-year lectionary, and the answer is.......yes.

From his post:

Years ago, the Pontifical Commission "Ecclesia Dei" clarified that the new Lectionary, for the Novus Ordo, could be used with the older form of Mass. It could be used.

I have no idea how this would be done. But… there it is.

Personally, I don’t know of any place where that was done. It is hard for me to imagine a group who would want that.

However, I don’t believe that a close reading of Art. 6 bears an interpretatio that only approved editions of Readings for the OLDER Mass and only the older Mass can be used. The Art. 6 surely includes approved editions of the Novus Ordo Lectionary.

UPDATE:

In 1991 the Pontifical Commission "Ecclesia Dei" issued guidelines to the bishops of the world. Here is the relevant passage:

5.Following upon the "wide and generous application" of the principles laid down in Quattuor Abhinc Annos and the directives of the fathers of the Second Vatican Council (cf. Sacrosanctum Concilium, nos. 51 and 54), the new lectionary in the vernacular could be used as a way of "providing a richer fare for the faithful at the table of God’s Word" in Masses celebrated according to the 1962 missal. However, we believe that this usage should not be imposed on congregations who decidedly wish to maintain the former liturgical tradition in its integrity according to the provision of the motu proprio Ecclesia Dei. Such an imposition might also be less likely to invite back to full communion with the Church at this time those who have lapsed into schismatic worship.

End Fr. Z., begin Dan's commentary:

I think this basically vindicates the position I was taking the other day, along with what Drew and I were sorting out in the comments. By no means should this kind of thing be imposed upon anyone with an existing tradition surrounding celebration of the extraordinary use. However, I think it could be potentially very fruitful for pastoral implementation, especially where time constraints on the part of a given priest might be make or break for whether an extraordinary Mass could be celebrated each week. On this basis, it would seem to me that having an extraordinary Mass with the 3-year cycle of readings would be significantly better than not having it at all, since one still has everything else that comes with such a celebration.

Briefly speaking, here are the obvious areas where use of the 3-year lectionary would require a bit of work to match the 1962 calendar correctly (I expect to speak more about this over time, but these are Sundays, when I would expect the vast majority of extraordinary Masses in the near future to occur):
- The Septuagesima season, which does not as such exist in the newer calendar
- Christ the King Sunday, which occurs on a different day

Once again, the purpose of discussing these matters here is to make the extraordinary use as widely available as possible, not in any way to dilute it or to question the great value of the traditional pericopes. It is to say that if we want this wonderful Mass to encounter the larger Catholic world outside of traditionalism in the broadest possible way, it makes sense to employ every allowable option given for it by licit authority in order to do so. While we may disagree on the merits of the 3-year Lectionary, there is nothing about it that ought to give scandal. It is still the word of God, in a form authorized by His Church, and one may hope that an encounter with the extraordinary form may help to point out the weaknesses that are there for the purpose of improving this Lectionary in the future.