It's still being investigated, but early indications are that the Linux 3.11 kernel is consuming less power at least for Intel CPUs.
As part of my usual Linux kernel benchmarking roundabout, I've been testing the power consumption on the Linux 3.11 kernel compared to its predecessor. On an ASUS Ultrabook with Intel Core i3 "Ivy Bridge" processor, the power consumption is doing better than with the Linux 3.9 and Linux 3.10 kernels.
Testing is still ongoing and I'm in the process of testing out Intel Sandy Bridge and older notebooks to see if the lower power trend continues there, hence just this quick one-page posting before the weekend.
Those interested in the Intel Ultrabook power consumption numbers on Linux 3.11 along with some other benchmarks, they can be found on OpenBenchmarking.org within 1307262-SO-LINUX311K00.
With the Phoronix Test Suite it's easy to reproduce this testing by just setting the PERFORMANCE_PER_WATT=1 and MONITOR=sys.power environment variables and then run any and all benchmarks you wish to simultaneously matter the Linux battery power consumption via ACPI (or a USB-based WattsUp power meter).
Stay tuned for more information over the weekend and next week on Phoronix as the Linux 3.11 kernel power consumption is explored in closer detail while now you can analyze the current data.