A very partial list, in no particular order:
1. Many false teachers have risen up, claiming to teach Catholic doctrine, but instead teaching grave error.
2. The number of false private revelations has increased dramatically in recent years.
3. The leadership of many Catholic universities, colleges, and other Catholic organizations openly reject the teaching of the Church
4. Most Catholic theology departments are filled with heretics and other persons unfit to teach the Faith.
5. A large percentage of men and women religious have rejected the Church as teacher, and instead embrace every teaching of sinful secular society.
6. Most Catholic young persons do not believe or follow the teaching of the Church on sexuality.
7. Most Catholic married couples use contraception.
8. Most Catholics approve of contraception, artificial procreation, homosexual marriage, and many other sins.
9. Most Catholic hospitals do not follow Catholic teaching on contraception, sterilization, and abortion.
10. Most Catholic politicians do not speak or act according to Catholic teaching, especially on abortion, abortifacient contraception, contraception, religious freedom, same-sex marriage, human cloning, embryonic stem cell research, and artificial procreation.
11. Most Bishops refuse to excommunicate or otherwise strongly rebuke teachers of heresy, unfaithful politicians, and other prominent Catholics doing grave harm to souls.
12. Most Bishops and parish pastors refuse to ensure that leadership positions in the diocese and parish are held only by persons who believe and practice the Catholic Faith.
13. Most Catholics worldwide do not accept the Church as their Teacher on any topic at all.
Some particular events that reflect this progress toward the great apostasy:
a. An entire parish rejects Communion when told not to receive if there were unworthy:
“VIENNA, Austria — The parish church of Amras, Austria, near Innsbruck in Tyrol, was chock-a-block full for the first-Communion Mass on April 22. Shortly before Communion, the parish priest, Norbertine Fr. Patrick Busskamp, announced that only Catholics who were in a state of grace should come forward to Communion. Catholics who are divorced and remarried and Catholics who do not attend Mass every week were not worthy to receive the Eucharist, he said. When Communion time came, not a single adult came forward. The entire congregation demonstratively remained seated. Only the children received Communion.” [Source]
b. Cardinal Schönborn approved of the election to a parish council of an active openly gay parishioner, living in a civil union with another man. My post on the subject.
c. When an openly lesbian Buddhist woman, living in sin with another woman for over 20 years, was denied Communion by a priest, the Bishop apologized to the woman and removed the priest from his ministry. My posts on the incident.
d. The U.S. Bishops speak out strongly against the HHS Mandate, that would require Catholic employers to pay for contraception and abortifacients, but they do not excommunicate the politicians involved, nor do they speak anywhere near as strongly against contraception itself.
e. Teachers of heresy abound on the internet, and their fellow Catholics find nothing objectionable in their writings, despite many grave doctrinal errors. A few examples of these false teachers: Fr. Ryan Erlenbush | Jimmy Akin | Michael Voris
When does the Great Apostasy occur?
In my eschatology, this event begins this very year, in 2012, not long after the election of the next Pope. Then, when that Pope is martyred, these apostates (who will include some Cardinals and Bishops) will attempt to set up their own Church, with their own Pope. There will be, for a brief time, two persons who claim to be Pope: an antipope and a true Pope.
More on this topic in my eschatology book:
The Future and the Popes