SEASON PREMIERE: For Cycle 12 of this competition dance series, Fox is trying to make enough changes so this show can remain vital, or at least viable, for a few more seasons. The biggest structural changes are in the competition – it’s now stage vs. street, not men vs. women – and in the judges’ table, where Mary Murphy is gone, and a familiar judge from an even older Fox competition series, Paula Abdul from American Idol, signs up for the entire season. And since she started as a Laker Girl and choreographer, she’s more than qualified for this up-from-the-streets showcase.