Four weeks into the 2007 NFL season, we can start to see how certain teams are shaping up. Four teams sit undefeated - Dallas, Green Bay, Indianapolis and New England.

Though many may have expected the Super Bowl Champion Colts to be on top of their game, I'm not sure how many pundits would have predicted such a hot start for the other three teams.

In Dallas, some may have worried about Tony Romo's psyche after his botched snap knocked the Cowboys out of the playoffs last season. But the young Dallas quarterback is playing phenomenal, tallying 1,199 yards passing, 11 touchdowns and only three interceptions through four contests. Only two quarterbacks in the league have accumulated more passing yardage - Green Bay's Brett Favre (1205) and Detroit's Jon Kitna (1227).

Speaking of Favre, he may be the biggest surprise in the league right now. The Packers quarterback will be turning 38-years-old this week, but he hasn't missed a beat. With eight touchdowns and only two picks, Favre hopes to keep Green Bay undefeated this week as they take on the Bears defense on Sunday.

In New England, Patriots Tom Brady has been carrying the team without a legit long ball wide receiver for years. However, that all changed this offseason with the addition of Randy Moss. On the season, Moss has already caught 31 passes for 505 yards, including seven touchdowns. Moss is currently leading the league in reception yardage.

At the opposite end of the spectrum, the New Orleans Saints and St. Louis Rams are still looking for their first win, while several other teams are struggling at 1-3, including the San Diego Chargers who finished last season with a record of 14-2.

In another news, Travis Henry of the Denver Broncos is leading the league in rushing yardage but his season is in doubt.

After violating the NFL drug policy, it is expected that Henry may be suspended for one year. However, Henry is adamant that he is going to continue to play as he plans to appeal the decision.