When is Vatican III going to occur? I used to think in the next 20-30 years. I no longer think so. I think it won't be for another 80-100 years.

I don't think there's been a vaguer set of documents than those of Vatican II considered collectively, and that is actually a good thing. Vatican II's style is more in resonance with the human spirit, but does not do much for controlling types, i.e., the powers that be. If there is going to be a Vatican III. I'd suspect that they would want two things to happen; first, that Vatican II be blurred by time and secondly, create a theological distance from Vatican II by the promulgation of many encyclicals in the interim.

Liberals love Vatican II as is, but conservatives, I think tend to bristle at parts of it. The popes since Vatican II have tried to theologically rein in the free spirit of Vatican II and few more encyclicals should do the trick. Not to question their motives, but I do think the Council hit on something special that in the context of the Church's administration would be very difficult to maintain.

One example that jumps out is Dei Verbum VI (the last chapter). It was the desire of the Council that the Word of God would be venerated as much as the Eucharist . They wanted to elevate the Word of God to that level so that Catholics would have as much of a devotion to the Word as they have to the Eucharist. Well, that fell flat on its face. One thing to note is that there is not much gained in terms of control if the Word receives as much attention as the Eucharist, on the other hand, the interests of the powers that be are maintained and protected if devotion to the Eucharist is unrivaled.

What's my point, as one who loves phenomenology, I like to examine the hidden assumptions of what appears plain, assumptions and presuppositions that people exercise unconsciously. There is much risk in exposing Catholics to the Word, (i.e., reformation) such exposure must be done in a very controlled environment, on the other hand, there is little to no risk in exposing Catholics to Eucharist. Now, some may contend that Sacrosanctum Concilium, states that the Eucharist is the source and summit of the Christian life. Herein lies the tensions and ambiguities of Vatican II. It is no secret that the conservatives got their way with Sacrosanctum Concilium but the progressives scored a major coup with Lumen Gentium, and further with Dei Verbum and Gaudium et Spes is just off the charts.

I think Vatican II did something that cannot be undone, it set the Church on a path it is not yet ready to take, nor do the powers that be necessarily want to go there. As a result the pendulum will swing the other way, because that is what pendulums do. But Vatican II has shortened the arc and will force the issue and force new considerations a century down the line.

What new considerations? If you are still alive then, then you deserve to know and you will know then. I'd be betraying God's trust if I told you.