We all know the great work done with the GPU Mali 3D accelerator by Lima project, the open source driver performs better than the binary blob which ARM sells.
The Mali is used for 3D graphics i.e. used mostly by the games rendering engines and 3D CAD software.
Beside the GPU Allwinner chips have also VPU which can do hardware encoding and decoding of audio and video, as you guess VPU drivers (http://linux-sunxi.org/CedarX) are again made as binary blobs, so these were not used in the Linux Kernel and distributions.
A group of hackers (jemk, wingrime, nove) worked on the reverse engineering of CedarX http://linux-sunxi.org/CedarX/Reverse_Engineering.
Yesterday was announced that there are already preliminary open source CedarX drivers for Allwinner SoCs.
On this video you can see tablet with A10 playing video using the hardware decoding without using the CedarX binary blobs http://www.youtube.com/watch?v=z__RxeVmYCQ
This makes Allwinner SoCs one step ahead all competitors as the GPU/VPU proprietary blobs is what makes most of ARM devices not completely opened.
All Linux implementations so far were not using these co-processors like the GPU/VPU which made the video operations slow as done completely by software in the main processor. Now when Open Source drivers exist the main processor will be released from video and graphics related tasks which will increase remarkable the speed.
Allwinner SoC thanks to open source community now is one of the most Open Source friendly SoC with: Open Source bootloader (contributed by Allwinner), Open GPU (lima project), Open VPU (cedarus).
Still lot of work is to be done, but liberating the video decoding is something which many people were waiting – Allwinner CedarX drivers were among the top priorities of FSF http://www.fsf.org/campaigns/priority-projects/reverse-engineering