Unfortunately, Msgr. Lefebvre went ahead with the consecration and hence the situation of separation came about, even if it was not a formal schism (http://www.30giorni.it/us/articolo.asp?id=9360).
Speaking to the bishops of Chile in 1988, shortly after the illicit consecrations of Archbishop Lefebvre, our current Pope gave all Catholics sufficient words of reflection to ponder:
We must reflect on this fact: that a large number of Catholics, far beyond the narrow circle of the Fraternity of Lefebvre, see this man as a guide, in some sense, or at least as a useful ally. It will not do to attribute everything to political motives, to nostalgia, or to cultural factors of minor importance.
These causes are not capable of explaining the attraction which is felt even by the young, and especially by the young, who come from many quite different nations, and who are surrounded by completely distinct political and cultural realities.
Indeed they show what is from any point of view a restricted and one-sided outlook; but there is no doubt whatever that a phenomenon of this sort would be inconceivable unless there were good elements at work here, which in general do not find sufficient opportunity to live within the Church of today.
For all these reasons, we ought to see this matter primarily as the occasion for an examination of conscience. We should allow ourselves to ask fundamental questions, about the defects in the pastoral life of the Church, which are exposed by these events.
To be honest, I don't know what this means. It seems to me that the SSPX is in schism as long as it insists on remaining outside the regular lines of authority of the Catholic Church after having consecrated bishops against the Pope's explicit command not to do so.
I agree that many of those who attend services at SSPX churches do so in good faith, and I would like to see the Society come back into full communion with the Church.
It seems to me that the major issue is whether the Church is willing to regularize these bishops and priests, and whether it is willing to permit them to continue saying the Old Order Latin Mass. I think it was a huge mistake to abandon the Latin Mass and to allow liturgists to play arbitrary games with it, abandoning thousands of years of tradition.
Some of the regular bishops appear to me to be heretics, but they are not in schism. The whole business is regretable. I know that Pope Benedict has indicated he would love to go back to the old rite, and to the old orientation of the priest ad orientem instead of ad populem. But the question is, how to accomplish this without causing further schisms and breakaways. It's a mess. But it would be a good start if the SSPX can agree to come back into full communion with the Church.