1 Super Bowl in 14 years... does not make Manning the "savior" or the Niners contenders...
You still must read in between the lines before you go off and point out that fact. Fact of the matter is, is that Manning has been to countless number of AFC Championship games and two Super Bowls, winning one and earning Super Bowl MVP honors. He's also been an All-Pro his entire career and won NFL MVP numerous times as well.
If his resume is ANY indication, Manning will give his new team a 12 win season consistently for the rest of his tenure in the NFL and with that not only comes a chance at winning the division, but the #1 seed in the AFC/NFC playoffs. Manning's health plays a good part in all of this, but an 80% Peyton Manning will go a LONG WAYS for teams and owners foaming at the mouth to win a championship who hasn't had that taste for quite some time.
If Manning goes to the '9ers, they are automatic NFC favorites and most people will pencil them in as 2012 NFL champions. Thing what is scary to me, is that in all of those 14 years in Indianapolis, he has never played with that great of a defense (minus Freeney/MAthis) OR a consistent running game, especially when Edge left so for him to play with the likes of Patrick Willis and then not only have Randy Moss, Mario Manningham, Vernon Davis, (possibly Mike Wallace) but a bruising style running back in Frank Gore with a scrappy offensive line is terrifying. They'd be the most complete team BY FAR within this last decade or so.