Red Bull Racing have brought another aerodynamic step to its car at Singapore, and most notably that includes a new diffuser. The new design has changed mostly in the centre part of the car, around the double decked area. Where the older version focused on speeding up air on the lower channel, the new iteration has a bigger central channel around the crash structure to profit more of the DDD design. The central part is now very similar to the Renault or Brawn diffusers.
One detail marked in the image however are two small pointy extensions on both sides of the diffuser. Red Bull carefully copied that from McLaren and clearly found the additions efficient enough to use them.