According to Mac Rumors, the latest MacBooks might have an unannounced new feature: GPU-accelerated h.264 codec decoding.

According to anecdotal evidence, the new aluminum MacBook’s processor runs around 75% slower when playing back 1080p movie when compared to a last-gen MacBook Pro with the Nvidia 8600M GT.

That makes sense: the MacBook’s built-in 9400M chip is designed to support offloading video decoding to the GPU. But it’s nice to see confirmation; more over, it seems to hint that we’ll be seeing a lot more high-definition content on iTunes, sooner rather than later.

Apple Enabled GPU Hardware Decoding of h.264 [Mac Rumors]