The best thing to glean from this poll is that Romney is pretty popular in Michigan and will likely bring the state close to being a tipping point state.
The Romney name remains popular in Michigan due to a Governor from the 1960s -- before the state became an economic disaster. Mitt Romney could make Michigan a single-digit win for President Obama. But that said, Michigan has an unusually-high number of African-Americans for a Northern state, only Maryland and perhaps Virginia (if you now consider Virginia a Northern state) having higher proportions of black people.