According to the Google+ status, Marvell and Nvidia will provide the CPU module for the Project Ara. The Project Ara is a modular smartphone, allow you to swap out any of components like CPU, camera, screen, battery and more. With that, you can easy to upgrade your smartphone hardware by select components from suppliers and assembly it back.
Apparently, if more processor manufacturers participate this project beside Rockchip, it looks like when the Ara available to the mass market, users have a lot of CPU modules to choose.
Marvell PXA1928 and Nvidia Tegra K1 processor modules
Both Marvell and Nvidia are confirmed they will supply SoC modules for Ara. Powered by a quad-core ARM Cortex A53, the Marvell PXA1928 SoC supports all global broadband standards and has a high performance internal memory architecture. Also the Nvidia Tegra K1 based on a 2.3 GHz quad-core ARM Cortex-A15 processor and can be paired with up to 8GB RAM, supports high resolutions up to 3840×2160.
So, with the success of Project Ara, Google will be looking for more components supply companies like RAM, memory, camera, battery and so on. Do you think the Ara will become like your desktop ? Easy to upgrade ?