From the ACLU:

A federal court announced today that HB 56, the Alabama immigration law, has been temporarily placed on hold. The law was scheduled to go into effect on Sept. 1. The temporary hold was ordered to give the court sufficient time to issue a decision on motions filed in three consolidated lawsuits to block the law, pending a ruling on the motions.  The court's temporary order does not reflect any view about the substance of the motions.

The hold will remain in place until Sept. 29 at the latest, and the court is expected to publish its decision on the three pending motions by then.  The motions were filed by a coalition of civil rights groups, the United States of America, and bishops of the Episcopal, Catholic and Methodist churches in Alabama.