It looks like Mike McGrath is in. The man who won his second term as Attorney General while uncontested is the first announced candidate for chief justice.
McGrath goes into this the prohibitive favorite. He is well-respected, has solid fundraising ability, and is popular in the state. Plus he just has high name ID. Anyone looking to mount a challenge will definitely think twice.
On top of that, McGrath will no doubt be a good chief justice. The job of the chief justice is to be a justice, which McGrath will likely do well, and oversee the administrative end of the court. McGrath has managed fairly large operations and comes in with a background that will be helpful.