In one of their latest reports the biggest energy research centre in Holland takes Peak Oil seriously.
The report is called four European Energy Futures and can be downloaded here
http://www.ecn.nl/docs/library/report/2005/c05057.pdf
It has a specific part of 10 pages about Peak Oil and why the timing of Peak Oil is important. It states the So called Doomsayers (according to ECN) arguments and why they have a lot of validity.
It's conclusion is: Why the doomsayers are right.
They base their 4 scenario's on Peak Oil and Global Climate Policy.
in 2 of their 4 scenario's Oil production Peaks between 2010 and 2020.