It's no slam dunk that former 49ers head coach Mike Nolan will be hired as the defensive coordinator, but that's what I'm expecting because of his history with Mike McCarthy in San Francisco. Nolan has a solid resume and can obviously coach in the NFL, so hiring him is fine with me. I'm more interested in how GM Ted Thompson revamps the defensive line, then in how Mike McCarthy revamps his defensive coaching staff.
It's good to see McCarthy kick the tires on a couple other candidates. Gregg Williams is just as accomplished as Nolan and well worth an interview. Also, he's checking out a promising young coach, Philadelphia's secondary coach Sean McDermott. Plus he's keeping his inhouse options open by retaining assistant head coach/linebackers coach Winston Moss, although I haven't read that Moss has had an official interview.
Niners Nation, the 49ers blog on SB Nation, they kicked the tires on whether the Packers should hire their former head coach. They aren't really sad to see Nolan gone in San Francisco, so they aren't really impressed that the Packers are considering him as a defensive coordinator. I added my two cents in the comments. Go over and read the post to see if Mike Nolan would be a good hire.