The 49ers are in prime position to win the NFC West. Jim Harbaugh has San Francisco going on the road and beating big-time teams like the Philadelphia Eagles. Both the Seahawks and Cardinals are two games behind with only four weeks in, and if San Francisco can keep on winning, they're in good shape.
Oakland isn't quite in as good shape as San Francisco, but they also have a good shot to win. The Raiders will have to keep up with the Chargers though to ensure they're in a position to overtake them when they face off a month from now.