in order to reach higher clockspeeds, you need to add voltage right? which then adds heat. which causes a system to become unstable w/out proper cooling...this much i already know
what other problems are possible w/ higher voltages?
if your overclocking "new" hardware when it's still new, your going to get rid of it before it dies anyways... so toast em while you got em!!
oh, and btw, my 300a is still running at 450, i think it's been off for 2 days while moving since i got it... so i've never seen any bad effects of overclocking...
Well I suppose it may shorten the actual life from 10 years down to maybe 3-5 years. But who cares, as most people on this list probably are changing CPU's at least once a year. Just remember to sell your OC components either to a fellow OC or someone you don't know