Hi Joel,
Shunning is the ultimate tool, but not the only tool, used by a cult to hold its members in line. However, I don't believe that it is possible to undo it as part of the JWs theology. It's one of the many tactics the cult uses very effectively to hold its members in line.
I believe that the only way that you'd ever see any movement away from it would be to have a "reform" movement of JWs who basically say "we're mad as Hell, and we aren't going to take it anymore." Of course, that will lead to the dissenting group being "shunned". But, at least they could move away from shunning. However, there will always be staunch adherents to the "orthodox" JW style who will not budge. It works for them. [Admittedly, in a distorted, antiseptic approach to life.]
I believe that this schism will actually take place in a relatively short period of time. With the Internet's wealth of information exposing the JW serious weaknesses, the most probable TV expose of their hidden child abuse, and more people just starting to talk and question it just has to fall from its perch [we can already see the cracks in the foundation among the declining western world membership].
But, sadly, I believe that shunning will always remain part of the theology for the orthodox few remaining.