i've had my Ps3 for 3 years, no YLOD. the key is actually take CARE of it, instead of leaving it on all day.
like humans, it needs a break, or it will overheat.
i suggest every week, or every other, take a low power vacume and blow the vents out, and every month, wipe it off with glass cleaner, that's my way to clean it, and make sure the environment is not too hot, or it will be more likely to overheat, remember
IT'S ALL ABOUT TAKING CARE OF IT.