To further complicate things, Michigan doesn't use the NEC for one and two family dwellings. They are covered by the Michigan Residential Code. On March 9, 2011, they adopted the 2009 International Building Code as Michigan's 2009 Residential Code. They did not, however, extend arc-faults beyond bedrooms. Here's a link to a state webpage with some info: http://www.michigan.gov/lara/0,1607,7-154-10575---,00.html
Note that they are happy to sell you a copy for only $81.50.