Have my launch 60gb and ever since it started running hotter because of the updates I was running it less and less.
Until recently I ran it to swap the data with a new slim ps3. Also running it with a 120gb OCZ Vertex 2 SSD drive.
But yea even after swapping out the 15 blade fan with an OEM 19 blade and ICQ7 thermal paste, placing it on top of 4 tins of .177 pellet ammo and a small fan in the back to blow the hot air away. AND it would still get extremely hot, too hot for my liking.
After some research a couple months ago, some owners started a thread on another forum about how the ps3 can run cooler (especially if its the launch or backwards compatible) and they found out the PSU in these systems is running extremely hot. So the best mod besides swapping in a 19-blade fan is to swap out the power hungry, less efficient PSU.