Bob Wolfley found a ranking of NFL head coaches that has Mike McCarthy as the 16th best. It's easy to pick apart the ranking. If his team has been winning lately, he's ranked high. If he's a rookie head coach, he's ranked low. It was done by RealScouts, a group of former NFL scouts working for the Sporting News, so they are knowledgeable guys, but it's a lazy ranking. If the Packers win the NFC North next season and the Vikings miss the playoffs, it's guaranteed RealScouts would rank McCarthy over Childress next season (currently Childress is ranked 11th). But it wouldn't mean McCarthy suddenly became a better coach.

Is McCarthy good enough to lead the Packers to a Super Bowl win?

They came very close to a Super Bowl two seasons ago, so he isn't holding the team back. But he couldn't magic a Super Bowl run in 2008 out of a team that couldn't run or stop the run.

The most important thing a head coach can do is put good players in a position to succeed. Also, he has to realize when something isn’t working on a particular Sunday for a player(s), he has to make adjustments, maybe even take some chances. I don’t know what the percentage is, but I bet few head coaches take any major risks. That’s hard, and I’m sure sometimes on field adjustments are just dumb luck.

• He is good in utilizing his players. He asks QB Aaron Rodgers to move around the pocket, he's outstanding at throwing on the run, but doesn't ask him to run for yards. He gives his offensive lineman some help from a back or tight end if they need it in pass protection. He doesn't ask a lot from guys that are good, but not great, receivers like RB Ryan Grant, FB Korey Hall, and TE Donald Lee. He knows what his players can do.
  
• On offense, he seems to make few adjustments during a game. He keeps the offense varied and generally sticks with his game plan. He'll call more pass plays if they're trailing, but that's what every team does. While it would be great to see him get into the other coaches head and perfectly counter-scheme during the game, that's asking him to develop a skill that no other coach has. He's not outstanding in this area, but he's not a liability either.
  
• He takes few risks on the field. Maybe he calls one or two trick plays per season. He doesn't start benching veterans at the first sign they've entered his dog house. A head coach has to be a steady influence on the team. If his players see him calling wild plays, or benching players on a whim, they have to lose confidence in him, and that can't help the team. On this point, he is a good coach.
• Although he's watching how his defensive players are doing and evaluating the defense overall, he gives his defensive coordinator a lot of room to work. He didn't appear to be forcing changes on Bob Sanders or Mike Stock as they ran the defense and special teams last season, he gave them a chance to coach their way out of bad seasons. But he let both go when it was clear he lost faith in them. It's clear he's doing a good job delegating, but it's also clear who's in charge.
  

A head coach also has to project the image of what players and media expect in a successful head coach. Usually that doesn’t translate on the field, if you don’t have the players it really doesn’t matter how awesome the locker room is. But it does help a head coach keep his job. Winning is still the most important thing, but if the coach loses the PR battle (i.e. the media and/or the players dislike him) and he has one losing season, that coach will probably get fired, just like what happened with Mike Sherman.

• The Packers' locker room seems to be solid. They aren't known for signing big ego free agents or drafting problem children. Part of the reason they stuck with Rodgers over Favre last year was to let the players know that they were going to stick with the player who worked hard in the offseason and earned a starting job. Obviously GM Ted Thompson has a lot to do with the personality of the roster, but I've never read any back stabbing of McCarthy by his players.
  
• He can get frosty with the media during press conferences, I doubt any of them are his golfing buddies, but the media seems to give McCarthy respect. He's got the media on his side.

Overall, he's not a mind reader or bringing a brilliant new scheme to the NFL. But he's a solid coach who keeps his head about him, uses his players appropriately, and does a good job of delegating. He knows what he's doing on the field and it appears that everyone around him respects him. There are many coaches in the NFL that you can say that about, but there are many that you can't. While he's probably not the best coach in the NFL, he's good enough to get them to the Super Bowl.