I jotted down some further thoughts (in Spanish) on the Concertación loss in last Sunday's presidential election. I can be found here.
Basically, I think that the Concertación lost because it lost its way. Frei was a symptom, not a cause. Now there is a chance to re-establish some fundamentals. Does it wish to continue being a coalition? Is there anything keeping the four parties together? Is it willing to make substantive changes to its internal institutions? Is it willing to rethink its ideas?