http://www.gizchina.com/2012/12/10/leaked-xiaomi-m3-to-get-tegra-4-cpu-lte-and-4-5-inch-screen/
Early reports surrounding the Xiaomi M3, which will likely launch mid 2013, suggested that the latest phone would incorporate an 8-core CPU, however it seems that those reports were blown out of preportion.
Updated rumours now suggest the Xiaomi M3 will come equipped with Nvidias latest quad-core chip, the Tegra 4 (which has yet to be officially announced, but is thought to be an LTE chip capable of running at between 1.8 2.0Ghz. Along with details of the CPU, it is also rumored the new M3 will get a larger 4.5-inch display from JDI (Japan Display Corporation) which will likely have a stunning DPI.
From our own knownledge of the Xiaomi M2 and we also expect a 12+ mega-pixel rear camera, and around 2-2.5GB RAM as well as the latest version of MIUI (possibly 4.2).