I'm on my original Macbook Pro (1,1), a 2.16Ghz Core Duo machine back from July 2006. I've had the fans, logic board, IO boards, airport card, heatsinks, keyboard, hard drive, and super drive replaced (various times under warranty). I sent the computer in as it was having trouble with only 3 days left on my Apple Care warranty and they replaced pretty much everything. Since then, I have acquired a friend's macbook pro of the same vintage and use that for spare parts if/when I need them.
I just recently cleaned out the dust around my fans, as well as oiled them, and my temperature has dropped from 79C down to ~45C, so I will use this machine until the next refresh, at least.