The device will most probably sport an upgraded version of the quad-core K3V2 Cortex A9 of the P6. According to the information, provided by the MIIT, the upgraded chip will provide better performance and lower power consumption due to the 28nm manufacturing process (unlike the 40nm chip in the P6) and the CPU speed clocked at 1.6GHz, unlike 1.5GHz in its predecessor.
Furthermore, it seems that a Mali-450 GPU will take care of graphics. The internal memory storage of the Huawei Ascend P6S has grown to 16GB in comparison to the 8GB in the P6. The leaked specifications indicate that the P6S will be 0.3mm thicker than the Ascend P6, hinting us that the battery in the device will be bigger and thus most probably provide improved battery life. It seems that the P6S' display size and other dimensions will most likely remain unchanged.
The Ascend P6S will still lack the option to expand its memory storage via a microSD card. The device is expected to come with Android 4.2.2 on board, and Huawei's own Emotion UI 1.6 shell will run on top of it.
Although the device is awaiting its certification, it is currently unknown when the Ascend P6S will be released, but according to unofficial information the successor to the one of the slimmest smartphones of 2013 is expected to cost around 2700 yuan (less than $500).