Philadelphia has been consistently a very good team (8 teams good enough to make a deep run since Reid/McNabb took over) and has only had one losing season. One of those seasons even came with Garcia at the helm instead of McNabb.
I don't really buy the "Kolb is an unknown quantity, so the Eagles are in trouble." line. How many teams have voluntarily let a McNabb or better level QB walk without an off field reason, like Cutler's feud with McDaniels?
Green Bay let Favre go...and Rodgers worked out great.
San Diego's not exactly broken up about having Philip Rivers at QB inatead of Drew Brees.
Montana/Young, maybe?
Because of that, I can say with a high degree of confidence that Philly will be a contender. The only other NFC teams I am confident will have winning records, if healthy, are Dallas (5 consecutive winning years) and Green Bay (Young, and possibly most talented team, but we'll see).
The reason I'm taking Philly over Dallas or Green Bay, OTOH, is pure sports superstition. The guys I pick never win (the last Super Bowl champ I picked right in pre-season was QB'd by a guy named Elway) so when in doubt I take the team I dislike the most.
Finally, R2A is right about Sanchez. IMO, he's the worst QB prospect to go in the first round since Akili Smith, and his play last year did nothing to improve my opinion of him. Go find a list of QB prospects from the last 15 years and look how well college starts correlate with pro success, then look at how few Sanchez had.