[Manic!]

Can anyone point to some manufactures information on hard drive life expectancy? My search skills seem to suck.

[!MiKrofT]

You're looking for MTBF field. Mean Time Before Failure. Usually listed in hours.

[Soundy]

And keep in mind that keeping your drives cool is paramount to their longevity...

[John]

There is not much on this topic. The best article might be this one. It's by Google.
http://static.googleusercontent.com/external_content/untrusted_dlcp/labs.google.com/en//papers/disk_failures.pdf

[InvisibleSoul]

And keep in mind that keeping your drives cool is paramount to their longevity...

Surprisingly, the paper John linked to below shows that this may not be true... even though I still believe in the principle of keeping hard drives cool.