"Another turning point in the last 10 years is that basically any PC made since 2000 will probably be sufficient for what most normal users want. We get increasingly powerful CPUs that most people just don't need."

That's being quite generous to the Pentium 4. Really the last 4-5 years is when acceptably good CPU power in any circumstance for normal users became the norm. The Core series of processors is what first gave us the sort of power that we've come to expect and Nehalem, Westmere, Sandy Bridge and now Ivy Bridge are all just improvements on that.

Also, according to cpu world, the original 80386 was done on on 1.5µm lithography.