Second in IT job growth is completely due to the auto industry, both the Big 3 and all of the suppliers. While they are good jobs, cost of living here is pretty cheap so jobs are only good paying relative to COL in those other areas (and it's mostly due to the vast sprawl of suburbs like you mentioned).
It does not include Ann Arbor, but Ann Arbor is a real small city compared to anything else that would pop up in those surveys.