When testing a clean install of Ubuntu 11.10 compared to a clean install of Ubuntu 11.04 on three different notebooks, for all three notebooks the Ubuntu 11.10 "Oneiric Ocelot" power consumption was dramatically higher.
For an Intel Core 2 Duo T9300 notebook with NVIDIA graphics, Ubuntu 11.10 is going through 10% more power on average.
For an Intel Atom 330 netbook with ION graphics, the power consumption is up by 4%.
With an Intel Sandy Bridge system, the power consumption with Ubuntu 11.10 is up by 52%. In other words, the battery life can be dramatically shortened with Ubuntu 11.10 compared to Ubuntu 11.04, not even to Ubuntu 10.10 that is on a pre-2.6.38 kernel.
And the system table...
Ubuntu 11.10 is using the Linux 3.0 kernel and not the Linux 3.1 kernel, which is drawing even more power. Changes with the Intel graphics driver are responsible for some of the power increase on the Sandy Bridge notebook, but still for the two other systems without Intel graphics, Ubuntu 11.10 only worsens the Linux power situation.
More testing after Oktoberfest with a greater number of notebooks and desktops as measuring their AC power draw via the Phoronix Test Suite. The power situation won't be improved at all in Ubuntu 11.10 since there isn't any fixes/improvements upstream and anyways the Ubuntu 11.10 kernel freeze is happening next week.