Laptops, power management, and Ubuntu

I'm a bit surprised by remarks like "if you hope to keep your drive for 3 years".  I'm used to
ide drives lasting 10 years and up in desktops.  I would _at the very least_ expect a drive to
last for the common lifetime of a computer.  These days i use a linux machine at least 3,
usually 4-5 years before performance drops too far behind.  Anything less is not an acceptable
"expected lifetime", to me.