I'd read news about the studies on stretching and stopped stretching at all, but later ran into trouble. Even still, I rarely stretch before a ride; only if I feel particularly (painfully) tight, and even then only for a minute.
But a herniated disk sent me to physical therapists, surgeons, pain managers, accupuncturists, and finally a chiropractor. The sumation of all their advice was that stretching AFTER working out, as part of the cool-down is very necessary. That said, I know this much to be true: In my case, if I go more than few days without stretching AFTER I ride, my back is in a terrible state and it takes several rides/stretches before I'm feeling limber. If I've been stretching AFTER rides, I can almost always pick up and ride nearly any distance I have time for, without any back pain. In particular, I seem to need to stretch my hip flexors/soaz(sp?).
Stretching may not be required for everyone, but nobody should dismiss it outright; especially if they have any pain; even if it seems unrelated.