I have a dv1000, and it can get "hot" on the bottom - but it is never a problem. I find no compelling need to measure the temperature. Sort of like a dog chasing a car - what does it do when it catches the car?
As long as it works (and it does), no need to be concerned.
The HDD is a Seagate 160 GB 5400 rpm. I gb RAM. No complaints.