Now we have Cortex-A9 as mainstream, Cortex-A15 as high-end productivity and Cortex-A7 as low power, budged/entry level.
The Cortex A12 IP has been finalized as of a couple of weeks ago and is now available to licensees for integration. The first designs will likely ship in silicon in a bit over a year, with the first devices implementing Cortex A12 showing up in late 2014 or early 2015.
So in near future we will have: Cortex-A57 as high-end, Cortex-A53 as entry level and Cortex-A12 as mainstream processors.
More info on Cortex-A12 is available on http://www.anandtech.com/show/7126/the-arm-diaries-part-2-understanding-the-cortex-a12/2