I guess I wouldn't ever consider a Mac mini to be a "builder's" machine, so perhaps that's the confusion point. I was thinking ATX case, select a mobo and PSU, CPU, etc, etc, and you know... build it. Those folks obviously aren't going to be buying Apple no matter what the performance is like.
After years of essentially stagnation of Intel speed (oh yay, we got 8% this year! whee!) it looks like we're back to the early days of the industry, when we looked forward to rather crazy leaps year after year. That is going to alter the landscape considerably within two years.
Maybe you're right, but I cannot for the life of me imagine how there are more people walking around who care about the brand on the processor, more than if it works well, provides more raw power, and at a reasonable price for those features.
I mean, hell, I'm a CS researcher, developer, and consultant, and *I* don't give a crap about whether the CPU has Intel or an Apple logo... I want it to be stable, predictable behavior, and year over year always faster. The risk is primarily whether the migration can be managed effectively, and Apple has experience pulling that off with very little hitch.