I also recommend Sergio Campos’s excellent analysis of the Court’s treatment of commonality. As he points out:
Setting aside whether the Court was right as to the merits of the plaintiffs’ evidence in support of a common pattern-or-practice, whether there is such a common pattern-or-practice is common to the class. That’s all the “commonality” requirement requires!
My own instant analysis? For better or worse, it rather looks like the Court is adapting Twombly/Iqbal to class action certification.