nah, dont worry, thats why there are the foam flaps, it brushes dust off before it can enter the ps3.
i have had my 80GB b/c version since 07. no problems since and my house is REALLY DUSTY like ill wipe it and the next day theres a thin coating on it already, and i have a shedding dog running around.
no problems yet.
if you do i have ONE thing,
if you put in a dirty disc a dirty disc will come out, so if theres ALOT of hair or dust then it will come out with lines, now regualr dust would be fine it gets pushed of by the flaps etc, but if its a thick coating just wipe i off.
also* those lines i mentioned are not really a problem wither, my discs never skip, freeze etc. dust isnt a majour problem but if it is ever in years you can use a vaccum, or even buy a 5$ lense cleaner disc ( has bristles on disc to clean it)
good luck. =]
email me your PSN.
mememememememememememem please?