Read anandtech's new article. google with "anandtech power analysis"
The trend is obvious... as arm tries to improve the performance on their chips, their power consumption increases. On the other hand, Intel is lowering the power consumption on their new chips while still improving performance.
As it stands right now, the Cortex A15 (arm's latest and greatest) is consuming more power than a 5-year old Intel low-end Atom (Clover Trail) manufactured on a 3 year old process, and with only a small lead in performance. When Intel releases their Clover Trail+ in a few months, we will all of a sudden find that Clover Trail+ is beating the A15 in BOTH power consumption and performance. The new dual-core medfield will do the same in the smartphone market. What we will see is, smartphones with medfield inside will outperform arm's phones in both performance and battery life. Check the latest Antutu benchmark leaks for proof of this.
Further off, in 2014, Intel is all set with Merrifield (for smartphones) and Bay Trail (for tablets) on 22nm FinFET process. In the cores, Broadwell will be ready on 14nm FinFET. Meanwhile, arm's fab are struggling to get to 20nm planar! There are serious questions on whether armv8 (A57) will make it's way into the market by 2015 let alone 2014.