Don't be too sure; total power consumption of the new Skylake CPUs is much lower, as is power use by the display, etc.
It really isn't. Base configuration 13" MBP specs:
2015: 2.7GHz dual-core Intel Core i5, Turbo Boost up to 3.1GHz, with 3MB shared L3 cache: 28 W TDP [0]
2016 (Touch Bar): 2.9GHz dual-core Intel Core i5, Turbo Boost up to 3.3GHz, with 4MB shared L3 cache: 28 W TDP [1]
Both chips use the same 14nm process, and there's no free lunch. The "refined" 14nm process for the Skylake chip is put towards a tiny frequency bump.
[0] http://ark.intel.com/products/84985/Intel-Core-i5-5257U-Proc...
[1] http://ark.intel.com/products/91166/Intel-Core-i5-6267U-Proc...
The 2016 13" non-Touch Bar Pro has a 54.5-watt-hour battery.
The 2016 13" Touch Bar Pro has a 49.2-watt-hour-battery!
The components in the 2016 models are more power efficient. But at some point you'll run into physics.
Apple may claim the battery life is the same as before when watching a movie (probably entirely HW accelerator offloaded by now), but if you're compiling code all day I wouldn't expect the new laptop to match the previous battery life based on the raw numbers alone.