[blackjackblax]

Stream-entry, at least from this document/paper, is said to be the point at which "wrong views" no longer arise.

From http://www.buddhanet.net/e-learning/intro_bud.htm (concerning Right View):
"The path to liberation from these miserable states of being, as taught by the Buddha, has eight points and is known as the eightfold path. The first point is called right view -- the right way to view the world. Wrong view occurs when we impose our expectations onto things; expectations about how we hope things will be, or about how we are afraid things might be. Right view occurs when we see things simply, as they are. It is an open and accommodating attitude. We abandon hope and fear and take joy in a simple straight-forward approach to life."

My working theory is that at this point their worldview shifts, they stop looking for some special/supernatural meaning or understanding and finally realize that things are just as they seem to be. Realizing this, there's no further question that the Buddha was right and his teachings are true (impermanence, not-self, conditionality, etc.), and the mind knows exactly what it has to do to abandon all suffering (by abandoning all the fetters, releasing all craving and attachment). This is the opening of the Dharma Eye, seeing the truth of reality directly and that delusions of a self/soul are false, no more than wrong thoughts the mind clings to.

Up until this point, it's all about this view or that view, with some element of clinging and delusion. After this, wrong views don't arise because the mind no longer looks to "think up" a reality, it sees the simple reality that's before thought. As "gross" as stream-entry is, with unwholesome mental states still quite capable of arising, at least that mind has found the truth and can't help but be honest with itself.

Edit Addition:
It would also seem that after this point, since the mind is firmly rooted in reality, the process of conditioning toward Nirvana is mostly on auto-pilot, as if the mind is being pulled instead of pushed toward the goal. It's the only real direction that the mind can go; it begins to unravel the deeper meanings, gain greater clarity, with frequent meditative fruitions that lead to once-returner and beyond without any great effort.