Red Bull develop jagged barge boards
Red Bull have recently developed a new barge board and introduced it at the Australian GP. It was used again in Malaysia and is likely to stay on the RB4. The new carbon panel also features a jagged upper edge, similar to Ferrari's design of several years. The jags are however not rectangular which makes it different from other designs.
Besides the main panel, there is a new, smaller panel ahead of the main barge board which helps direct airflow around the sidepods. The two boards are connected with a horizontal plane at the same height as the car's floor.
Also note the curl on the the extension at outer side of the barge board. It is currently a standard item on F1 cars and acts as a venturi for air that passes underneath.
The picture is too small to really see anything in the inset.