The article seems to imply that the effect is highly dependent on the "amount" of electricity going through a connection. With that in mind, how much does this occur on the scale of a CPU where the connection is only a few tens of atoms across but the power is measured in only a couple volts?
In microelectronics the voltage is low but the current density can be quite high, and that makes electromigration a more severe problem than in higher voltage macroscopic devices like motors.
Are you familiar with the field or have links to resources I can read? Basically what I want to know is how long will a modern core-i5 last before some transistor bridges and it dies? 10 years? 50?
It won't answer your question directly (especially if you just read the free material instead of obtaining the whole book) but it should orient you for further reading. Note that electromigration is sensitive to temperature. Running cooler can extend the lifetime non-linearly, whether achieved via lower duty cycles or more effective cooling methods. You need to know how many years at what temperature the processor will run, not just the dimensions of the conductors.