CNN:

A judge in Pennsylvania issued an injunction Tuesday temporarily barring the state from implementing the requirement that all voters must present an identification at the polls on Election Day.

The state may implement other portions of the law, the ruling said, and the voter ID portion of the law may be enforced in future elections.

From what I can gather, the poll workers can still ask for photo ID, but they cannot deny the vote to someone who doesn't have it.  The ruling applies only to this November's election.  The judge's order is appealable.