Niner fan here; looking forward to a good game and, hopefully, a Niner win. A matchup of two teams who got here with opposite philosphies. Both teams are equally good (collective talent; not saying Alex Smith is as good of QB as Brees) hence the 13-3 record, surpassed only by GB at 15-1. Who will win/cover? I think SF but I'm biased. Team successfully executing its game plan and limiting big mistakes will win the game.
Aside from fundamentals & execution, football is all about who wants it more? IMO, Niners have an emotional edge in this game. Niners were ambushed in the first pre-season game @NO. Look up the press clippings from that game and most in the media agreed that all exotic blitzes by NO were an overkill for a preseason game. While Niner brass and players were professional about it you can tell (listening to the players/coaches on the local radio/tv shows, etc) that it was personal.
In 2010, TB had no problem running up the score @SF and then gloating about it afterwards (calling themselves West Coast Killers). Many of the players TB did that to are still on SF team. TB, 3-1 at the time, visited SF on 10/9/2011. Bucs were humiliated (48-3) in the rematch. That is the only game SF put up 40+ points. Bucs lost a couple of key players during the game (Blount, etc) and never did recover winning only one game (against the Saints) for rest of 2011 season.
Harbaugh was not part of the TB game in 2010. Now add Harbaugh's ultra competativness to the equation as the preseason game at NO was his first game as an NFL head coach. Him and Fangio (defensive coordinator) are likely licking their chops. Brees better have his chinstrap good-n-tight as there will be a hell to pay.