Re: 49'ers will be back.
Seattle is not going to be a threat for the mere fact that Harbaugh>Carroll dating back to Stanford/USC.
The real team to watch out for and a serious dark horse/sleeper is Arizona. Their defensive is legit and in the last half of the season was really, really good. They're infused with young talent and a nice mix of veterans, I could easily see them as a 10-6 team if they can get any sort of consistent QB play (big if). That defense is young and hungry for sure. Calais Campbell is one of the best defensive linemen in the NFL, Darnell Dockett is a beast, Sam Acho/Darryl Washington are two of the best young linebackers in the NFL, and we all know P. Peterson is going to be the real deal. Not to mention one of the best box safeties in the NFL - Adrian Wilson. That defense is sick and only getting better.
Fisher will definitely right the ship in STL although I think it might take a year or two until they're competitive. Their defense is old and needs to be gutted minus a few nice young pieces like Long/Laurinaitis.