Seattle's surprising win over the New England Patriots left the Seahawks at 4-2 and tied with the 49ers at the top of the suddenly formidable NFC West.  Meanwhile, New England, a heavy favorite to win its tenth division title in the last 12 years, finds itself unexpectedly in a four-way tie atop the AFC East.  Here's what we learned:

1. New England's Secondary Needs Overhaul

Its been no secret that the Patriots defensive backfield is the Achilles Heal of this team, but Sunday's performance may have been among the most discouraging in recent years. 

Seattle rookie QB Russell Wilson, who came into the game with a less than stellar QB rating of 75.2, torched New England for 293 yards through the air with 2 TD passes against zero interceptions, good for a QB rating of 133.7. 

There was hope in Foxborough that CB Devin McCourty, after a disappointing sophomore campaign, would return to the form that made him Defensive Rookie of the Year season in 2010. 

Unfortunately for New England, McCourty has continued to struggle in coverage and seems to have lost the ball skills he demonstrated as a rookie.  The rest of the secondary is a collection of pedestrian talent that at best appears barely competent, and at worst, completely lost.  In the past, coach Bill Belichick has been lauded for pulling guys off the street, (and the WR depth chart) and getting production in the secondary.  It may be time to start trolling the waiver wires and the local bus station.

2. Tom Brady is in Obvious Decline

Okay, it may not be that obvious, but it's definitely visible.  While the defense will take the majority of the blame for the loss to Seattle, Brady was once again merely mortal, and contributed a couple of key mental mistakes that cost his team points, and ultimately, the game. 

First, there was his clock management at the end of the first half.  Much will be made of the intentional grounding call that cost New England a chance at a half-ending FG attempt, however, three plays earlier, Brady let the clock run down to 19 seconds before calling a time-out, losing about 10 seconds.  That's the sort of mistake a Brady in his prime never made.  Forcing the ball to a well-covered Deion Branch for his first interception of the afternoon was another mental error.  This wasn't a bad route, a bad throw, unexpected coverage, or any of those other excuses people will sometimes make for Tom Terrific, it was simply a very poor decision. 

Finally, taking the field with 1:14 left and needing only around 45 yards for a chance at a game winning FG, New England never challenged, with Brady making a throw to wide for Brandon Lloyd to catch in bounds, taking a sack, and then ultimately throwing short of the first down marker on 4th down.  Clearly, Brady is still an elite QB and the list of NFL teams that would jump at the chance to trot him out every Sunday is very long.  But the evidence that Brady is now descending from the heights of legend to an altitude of the ordinary is mounting.

3. Seattle is a Legitimate Playoff Threat

The Seahawks now own victories over New England, Dallas, and Green Bay, all among the short list of preseason Super Bowl contenders.  Pete Carroll has assembled an aggressive group in the Northwest that plays the game with a confidence that belies their modest recent accomplishments.  Defensively, the Seahawks field arguably the best backfield in the NFL, led by CB's Richard Sherman and Brandon Browner, and safeties Earl Thomas and Kam Chancellor.  (For contrast, no player on New England's defensive backfield would crack that starting line-up.)  This group was scorched for long stretches by New England's potent attack but managed to create two turnovers, keeping the Patriots within striking distance for QB Wilson's late game magic. 

As for the Seahawk's offense, they won't be confused with the Greatest Show on Turf, but with Marshawn Lynch and Sydney Rice, they should have enough weapons to score enough, provided QB Wilson continues to develop.  Looking ahead, the Seahawks have a schedule that makes a 10 win season a very real possibility, which should put them firmly in the mix for a spot in the playoffs.

4. Carroll was Right About Wilson

In the offseason, Seattle invested heavily in free agent QB Matt Flynn, believing they had secured the QB position.  When Russell Wilson was tabbed in the third round of the 2012 draft, the expectation was that Wilson would compete with incumbent Tavaris Jackson for the back-up job.  But after a strong training camp and preseason, Carroll surprised many by naming Wilson as his starter, while Jackson was sent packing. 

Wilson's performance through six games has been mixed with some calling for Flynn to replace him, but Carroll has stuck with his young playmaker.  Yesterday, that confidence paid off as Wilson played his best game as a pro, consistently keeping plays alive and taking advantage of New England's porous pass defense.  Best of all, he took care of the football, with the lone exception a forced fumble by Patriots phenom Chandler Jones.  In the NFL, fair or not, QBs are measured by wins, and right now, Wilson owns victories over two of the pre-eminent QBs in the league, Aaron Rodgers, and now Tom Brady.

5. Wes Welker can Still Play

After a contentious offseason that saw the Patriots and their star receiver fail to reach agreement on a long term deal, speculation has been rampant that Welker is playing his last season for the Patriots.  When the season began with teammate Julian Edelman getting more snaps than Welker over the first couple of weeks, the talk of Welker's demise reached a fever pitch. 

However, with an injury to Edelman, Welker has been called upon to lead the receiving corps once again, and he's delivered.  For the third straight game, Welker topped double digits in catches and gained over 100 receiving yards, this time against one of the toughest defensive units in the league.  If that's not enough, Welker replaced Edelman on punt return duties and added four returns for 68 yards.  Since his arrival, Welker has been Brady's most consistent threat, and when Brady needs to make a play, he looks to Welker first.  What's truly remarkable about Welker is his durability.  Despite his diminutive size, Welker has managed to stay healthy enough to play in 83 of 86 potential regular season games since his arrival in Foxborough. That's a level of production and consistency that will be in demand should Belichick decide to let him walk after the season.