Is Miller an Eighth Amendment "bombshell or baby step"?

I have the honor and pleasure of participating today in a fantastic Missouri Law Review symposium which is to explore the question in the title of this post.  This webpage details today's schedule of panels and speakers, and this page reports on these essentials of today's event:

This year's Missouri Law Review Symposium will focus on constitutional, practical and policy matters, regarding juveniles and sentencing more generally, that now challenge courts, legislatures and attorneys in the opinion's wake. 

On the constitutional front, in what ways are adult offenders who are subject to mandatory sentencing schemes asking lower courts to extend Miller, and how are those courts replying?  The Miller opinion extends the Court's "death is different" doctrine to mandatory life-without-parole sentences for juveniles: should that doctrine, requiring individualized sentencing, apply in other contexts?  How are state legislatures and Congress responding — and how should they respond — in designing sentencing procedures for juvenile homicide offenders?  What special challenges will attorneys face when representing a juvenile in a life-without-parole sentencing trial?  Morally, to what extent, if any, do recent discoveries in developmental psychology and neuroscience shed normative light for courts and legislatures on juvenile offenders.

Judge Nancy Gertner, Professor of Practice at Harvard Law School, will deliver the keynote address.  She will be joined by eminent attorneys, inside and outside the academy, to explore these and other important questions regarding criminal sentencing in general and juvenile sentencing in particular.