Yeah, this is a real concern for computer enthusiasts who heavily overclock their CPUs. Higher clock rates need more voltage to be stable, but higher voltages increase electromigration. So maybe bumping the voltage from 1.3v to 1.5v stops your computer from crashing, but it could also cause your CPU to fry itself in 2 years instead of 10.
I ran an I7 920 at 4Ghz for roughly 2 years at around 1.35V with water cooling (max was 55C on full load on all 4 cores).
After the 2 year mark the chip became unstable and over the period of the next 6 months the clock speed it would reliably maintain was 3.2Ghz. On that progression it would be down below its default rated speed of 2.6Ghz in presumably another 6 months or perhaps outright failed.
The current estimate is that Intel targets about 15 years for a CPUs life at the clock speeds they ship, overclocking can vastly decrease that.
