The odd thing, the hardest thing to comprehend, is how our reality continues to exist. The ground state of the universe is a vacuum. Void of matter and shielded from radiation is the quantum foam of field fluctuations and virtual particles that exist on the scale of Planck lengths.

The probable reality is not that the universe came from nothing, but that the universe is nothing. In a flat universe (which is what we believe we are) the symmetries of the universe cancel each other out such that, accounting for the mass and energy, the universe is a state where 0 = 0.

Could you expand upon how causality can cease to exist or what would cause (heh heh) such a thing?

There is the concept of the heat death of the universe. http://en.wikipedia.org/wiki/Heat_death_of_the_universe

Essentially, as particles expand and spread out, the universe will reach a point where there is not enough energy localized in one area to support anything.

Of course this is just one theory. etc etc