Phoronix investigates the leading cause of the recent Linux laptop power issues, you can read it over here.
""Mobile users are urged to seriously consider these results,
and possibly even avoid the Natty Narwhal...I hate to say it, especially
in an Ubuntu review, but the mobile edge goes to Windows for now...There
are also compelling reasons for folks to avoid [Ubuntu 11.04] at all
costs. Linux gamers should see substantial improvements, while mobile
users suffer a dramatic loss in battery life," were among the critical
comments that Tom's Hardware had in their Ubuntu 11.04 review as they
were referencing the power regressions I discovered nearly two months
ago within the mainline Linux kernel. As I mentioned on Sunday, the
Phoronix Test Suite stack and I have now nailed this major power
regression in the Linux 2.6.38 kernel that is affecting a significant
number of mobile Linux users. Here is what is happening and a way that
you should be able to workaround the serious regression should it affect
your computer system(s)."