Cortex-A12 fills a gap
Starting off Computex with an interesting announcement, ARM is talking about a new Cortex-A12 core that will attempt to address a performance gap in the SoC ecosystem between the A9 and A15. In the battle to compete with Krait and Intel's Silvermont architecture due in late 2013, ARM definitely needed to address the separation in performance and efficiency of the A9 and A15.
Source: ARM. Top to bottom: Cortex-A15, A12, A9 die size estimate
Targeted at mid-range devices that tend to be more cost (and thus die-size) limited, the Cortex-A12 will ship in late 2014 for product sampling and you should begin seeing hardware for sale in early 2015.
Architecturally, the changes for the upcoming A12 core revolve around a move to fully out of order dual-issue design including the integrated floating point units. The execution units are faster and the memory design has been improved but ARM wasn't ready to talk about specifics with me yet; expect that later in the year.
ARM claims this results in a 40% performance gain for the Cortex-A12 over the Cortex-A9, tested in SPECint. Because product won't even start sampling until late in 2014 we have no way to verify this data yet or to evaluate efficiency claims. That time lag between announcement and release will also give competitors like Intel, AMD and even Qualcomm time to answer back with potential earlier availability.