The Mac mini is cheap and has surprisingly good performance. It is the absolutely perfect gateway into Apple's next generation of computing. Someone at Apple should get a merit badge for including this in their initial launch because it was genius.
That there is a big initial spike in demand is completely unsurprising unless you were asleep at a wheel. Much much more interesting is going to be what these numbers look like after Apple burns through initial pent up demand. Won't see that for 6+ months.