As of writing this, Trump won Michigan by just about 13,000 votes. Is it known how many provisional ballots there are in Michigan that might tip the state to Hillary?
This answer is no longer timely, but the Michigan Secretary of State's office released a report on provisional ballots.
According to that report a total of 22,504 provisional ballots were cast. The vast majority were provisional because the voter did not provide an adequate ID at the time they voted.