There's a couple of different ways to look at that. One school of thought is that Norv Turner's Chargers are better poised to make their postseason runs because they are playing better football at the end of the year and not completely played out after the regular season rigors of a Schottenheimer led Chargers team.
I'm not a huge Norv Turner fan, but the team does seam to play better late in the season and into the playoffs under him. Everything from the way he structures his practices to plays he runs and playing time for key players is based on that.
With that argument, the Chargers have been a better team the second half of the season and most notably the past five week where they are in the top 10 in both run and pass defense and top five in INTs.
There's also a statistical case made that the Chargers are the unluckiest team in the league this season with a -3.4 game swing in their win/loss record.
That being said what causes me the most angst is Dallas Clark. The Chargers have been absolute garbage all year against TEs (they've given up the most receptions and yardage against) which reflects their poor play at safety. If Jamal Williams can dominate the inside and get consistent pressure up the middle than I like the Chargers chances.