From a credible source.
Besides Bob Parker, Richard Trost and Jay Drick are strongly considering a run for judgeship, and were at a State Bar Candidate seminar which covers ethics rules, campaign finance laws, and related matters. Do not be surprised if they jump in for one of the positions, especially if there is a vacancy from an incumbent. Parker and Drick both recently ran for judge in 2004. Currently, I do not know anything about Richard Trost.
The only incumbent so far confirmed for election run is recently appointed Theresa Brennan. She was also at the State Bar Candidate seminar.
As soon as we know more about the Livingston County Judicial Situation, we will keep you posted.