The Eagles will have a top 10 scoring offense, and quite likely a top 5. Now i'm not sure the Eagles offense is really that good. I think it looks better because of then number of series they get in a game being higher then other teams. The quality of Philly's defense is also mitigated by the same factor that makes their offense likely to be good. They will have more series, so depth should be a bigger issue for them then most teams, which is an area I think they are weak in. On a per drive basis according to a chart I saw on football outsiders the Eagles offense was 13th in points per drive and the defense was 15th in points per drive. Basically on a per drive basis they were a fairly average team. And that really fits with the Eagles team I saw in December, while not so much against the one on Thanksgiving, but I'm thinking that was more about our team laying an egg.
Their offensive line is worse then it has been in the past. Their WR corps is worse then it has been in the past. QB probably has some upgrade, unless Bradford goes down which is not unlikely due to a weaker line and being Sam Bradford. The RB's are at best a toss up I think. The WR corps has some talent, but not sure there's a #1 in there, not really even sure there's a #2 in there at least this year. The defense has a good starting front seven, but if what I've seen is correct falls off pretty fast. The back end is Maxwell and pray they don't throw that way.
I think Chip Kelly is an excellent football coach. Right now I'd say he's a questionable pro personnel man. In the NFL I think the former is more important then the latter, as long as its one person holding both jobs. That's why I think you see almost no HC/GM in the league any more. Something usually has to slip and its usually the GM side.