How hot do Core Duo (specifically HP dv1000) get underneath?
Depends on how the specific notebook is engineered. A
generic answer would be that there have been cooler running
CPUs in the history of notebooks, but Core Duo is not a
particularly hot one.
How noisy are the fans on the latest Core Duo notebooks?
Same as above, depends on the fan used- in general the
larger a notebook is, the more room for a larger 'sink (more
effective per a given CFM airflow) and more room for a
larger fan (lower noise:airflow ratio), BUT, notebooks are
all proprietary designs, a manufacturer could opt for a
cooling solution that doesn't exploit the larger notebooks'
size or just put more other features in that usurp space
that could have gone to the cooling.
A coworker claims turions run much cooler and advises to get that
instead
of an intel.
How will you use the system?
You can get manufacturer spec sheets for any specific CPU
from their respective websites, those will give peak power
(heat) figures though IIRC, Intel uses a number a bit meant
for typical which in direct comparison is a little lower
relative to true peak possible power. Even so, if your uses
are typical and don't run the CPU continuously at full load,
the differences in idle power should not be enough to
consider relative to other features of the particular
notebook.