Back when I was in college for CE, one of my professors was very concerned that testing CPUs would eventually be the bottleneck. That verifying that it was actually working correctly would be such a burden once the number of transistors reached a high enough level.
Of course, I never heard about this again. Ring a bell with anyone?
It's called functional verification. Some say it's 70% of a project. I think that number is exaggerated, but maybe 50% is more realistic.
My previous startup (http://eve-usa.com) sells million-dollar boxes that are essentially debuggers, just like gdb is for software, but for chips. Very cool.
Of course, I never heard about this again. Ring a bell with anyone?