There tend to be two elements of the common sense idea of ethics and morality. The first boils down to "what must I do, and what do I deserve to expect from other people?" In other words, the question of morality is about choosing between possibilities. Doing X is good, while doing Y is bad.
The second element is that of justification. There is a persistent search for some way to justify moral judgments and acts. Probably the most common justification has been the afterlife; be "good" or you'll suffer punishment after death. Other common justifications involve human solidarity, or God's holiness and authority.
So the standard moral discourse asks, what should we do, and why should we do it?
Between the 19th and 20th centuries, these questions ceased to be serious philosophical themes. The first question is dismissed as instrumental thought - ie, the insistence on making pure thought "practical" and "useful," as if thinking were nothing other than a factory for producing goods and services. The second question - why should we act in such and such a way? - is dismissed as slavish and repetitive. Acting because of another being's power is the very definition of passivity.
The old categories of ethics and morality have fallen into disrepute. Yet, the 20th century demanded a response from those that lived it, and the 21st century demands a response from us. Viciousness and exploitation were, and are, rampant. If the shining beacon of morality is discarded, than do all conceptions of justice, courage, wisdom and truth follow closely behind?
We must hope not. Alain Badiou, writing decades after the "death" of philosophy was declared, has said that the world (not God, not philosophers - the world) is telling philosophy to get up and walk. We must say the same to ethics.
And yet, we cannot pretend that Nietzsche did not write. We can't go back to the old way of doing things. New concepts must be created. I think the thinkers of the 20th century - and now those of the 21st - have had a common ethical project, and I think this project can be summed up in terms of the disruption of the totality. The disruption - and remaking - of the world. From Heidegger's call of conscience, to Levinas's encounter with the Other, to Lacan's traumatic encounter with the real, to Badiou's fidelity to the event - the common thread is the traumatic disruption of everyday life.
Ethics is coming back, and it will have no truck with humanism (reach your inner potential!) or liberalism (choose what you like, just don't hurt anyone else!) or theology (bow!).