The new LEGO Batman Battle Pod 5004929 is now at Toys R Us and is included in the 20% off promotion for LEGO Batman Movie sets. The regular price is $5.99.
I was not able to find these on the shelf but there was a box of them behind the service counter. There seems to be no limit to the number one might purchase.
They also do not seem to be available for sale online at toysrus.com so the link (which is required to post a deal) is to the other LEGO Batman movie sets on sale.