Looks like David Hildenbrand will have company. According to documents filed with the Michigan Secretary of State, Lori Wiersma of Grand Rapids has filed to run. You can see the filing document here:
Ms. Wiersma has not filed for a reporting waiver, which means that she could be a viable candidate. Wiersma is a Ministry Director at ACTION Wyoming, and is a member of the Christian Reformed Church, attending Shawnee Park (in the heart of the diminishing GOP stronghold on the southeast side). She endorsed Tim Doyle in his 2006 run for the 75th State House seat.