I typed about this briefly back in October, and was forced to revisit it again upon finding this link in my inbox this morning.
While, of course, anything is possible, we also have to be cognizant and compassionate of the reality that so many parents face.
The part that really stung me was when the author spoke of the regression that she's experienced with her son. Darus is only 4 years old, so I haven't yet noticed much, if any regression. My heart goes out to those that have.