You probably didn't see INTEL latest 3D(tri-date) manufacturing tech announcement.
We will see next year most of INTEL notebook CPU only consume 15W, which means most of notebook can last for 8-12 hours with single charge(assume 6 cell battery).
The new OakTrial CPU(just released last month) is on par with ARM chip. The one using 3D manufacturing technology will be consume 50% less power.
Read the article here.