Just two teams have managed to win back-to-back Super Bowls in the salary-cap era: Denver in 1997-98 and New England in 2003-04. So, clearly, there are significant challenges to repeating. There will be no sneaking up on anyone this season. The Eagles will have the proverbial target on their back against every team they play.
One of the most successful aspects of their offense, particularly in the second half of the season, was run-pass options. They caught a lot of teams off guard with them. They weren't the only team that used them, but they were more effective with them than anybody else.