I'm not sold on the Eagles just yet either, but they have beaten every team on their schedule so far and looked really good more often than not. In todays NFL it's really tough to be 4-0, which we can see just by looking at the current standings.
They have playmakers on both sides of the ball, which will keep them in almost any game. What has impressed me about the Eagles is the Lions and Jags both came out and punched them in the mouth early, but Philly flipped the switch. After falling behind 14 against the Jags the Eagles turn around and scored 20 unanswered points and although the score was close the game never really felt that way 2nd half.
Not buying them as the best team in football, but in a weaker NFC this year they are legitimate contenders, something I argued against heavily preseason.