The teaching in this area is hard for non-catholics to grasp. The concept that is misunderstood is invincible ignorance. The Church has always taught "There is no salvation outside the Church".
They cannot be saved who, knowing that the Catholic Church was founded as necessary by God through Christ, would refuse either to enter it or remain in it (cf. LG 14).
Does this mean that all non-catholics are damned to hell? Not neccessarily so, though we leave it to God's justice and mercy. Those who through no fault of their own do not know that the Catholic Church is the fullness of the truth, but would join if they did know and try to live their life to the best of their ability, following God's truth as best they can, MAY be saved. This is in line with Romans 2:4-8.
"the Gentiles who do not have the law, do by nature the works of the law.
They show the work of the law <written on their hearts>."
Is this a new teaching since Vatican II? It has perhaps been cleared up some but Ludwig Ott's pre-vatican II Dogma of Catholicism, which is considered a classic on Catholic theology stated it quite explicitly. There are many other pre-vatican II examples and man statements by Bishops and priests throughout the ages. Augustine for instance says "God is not limited by his sacraments"
This statement by Pius IX shows that the Church long before Vatican II did not rigidly say that all who are not Catholic go to hell.
Thus Pius IX, in "Quanto conficiamur moerore" of August 10, 1863, taught:
"God . . . in His supreme goodness and clemency, by no means allows anyone
to be punished with eternal punishments who does not have the guilt of
voluntary fault. But it is also a Catholic dogma, that no one outside the
Catholic Church can be saved, and that those who are contumacious against
the authority of the same Church (and) definitions and who are obstinately
(pertinaciter) separated from the unity of this Church and from the Roman
Pontiff, successor of Peter, to whom the custody of the vineyard was
entrusted by the Savior, cannot obtain eternal salvation."[28]
Pius XII condemned the teachings of Fr. Feeney who taught that all non-catholics go to hell. Here is what he said:
"It is not always required that one be actually incorporated as a member
of the Church, but this at least is required: that one adhere to it in
wish and desire. It is not always necessary that this be explicit . . .
but when a man labors under invincible ignorance, God accepts even an
implicit will, called by that name because it is contained in the good
disposition of soul in which a man wills to conform his will to the will
of God."
More here:
http://www.ewtn.com/library/SCRIPTUR/OUTSID.TXT