As you all know there is a fan test procedure for the ps3... so i searched the net for it and found that some sites indicate that this procedure is bad for your ps3 and other claim that there is no risk for the ps3 and you can only gain from it.
This is more of an opinion thing I believe... mine being: if you don't do it all the time I see no harm in performing a fan test to clean out the dust once and awhile. I have never tried it myself, but based on the videos and feedback I've seen from those who have it helps their consoles run quieter and cooler once performed. Others?
I tried the job on a friends 40GB PS3 as we were curious to see whether we actually gained anything from it. It ran slightly quiter then before I would have tried it on my PS3 but the 60GB procedure seems a bit to pointless really.
I don't think that it would harm the PS3... logically, if it would do any harm, the 'feature' wouldn't be there in the first place.. It's a fan test, so the fan should be able to handle the speed, etc...
I didn't try it yet, and I won't try it until I see there's a lot of dust building up, then I'll do it... like anything else, I think you should just avoid over doing it!