Thanks to the folks at Brothers-Brick for the heads up:
Power Functions IR Speed Remote Control recalled from U.S. and Canadian Markets
LEGO Systems is working with the US Consumer Product Safety Commission to voluntarily recall the 8879 Power Functions IR Speed Remote Control which poses a thermal burn hazard to users if the batteries inside overheat. The remote control units were sold separately (item 8879) or sold in the Emerald Night Train kit (item K1094) and Power Functions kit (item K8882).
1,618 units of the remote control units were sold in the U.S. and Canada between April 8, 2009 and May 6, 2009. LEGO Systems has received 4 reports of the remote control heating up after batteries were inserted. No injuries have occurred.
These remotes were only sold directly to consumers through http://shop.lego.com or the LEGO Shop at Home catalog and were not sold at any retail outlets. All consumers who have purchased this item are being asked to immediately stop using the remote control unit and to check to see if their unit is part of the recall. Purchasers will be contacted directly by LEGO Systems with information on how to determine if their IR remote control unit is part of the recall and how to receive a replacement remote, or they can access this information here.