The most important thing to remember about the “Fiscal Cliff” the Establishment types are obsessing over is that it is merely a law, not a Constitutional mandate. All it takes to change or repeal a law is a new law. That’s hardly anything extraordinary.
In other words, “going over a cliff” is a very poor analogy. It’s a curious kind of cliff, one that can be wished away at basically any time, even after one has “gone over” it. All Congress needs to do is pass a law retroactively repealing the “Fiscal Cliff”.
The nervous mobs that rule the fiscal markets may get a few jitters about the process until it is all settled, but there is approximately zero chance that the “cliff” will fully and lastingly go into effect with all its drastic measures intact.