I like Foles and wish him the best. He's playing for a contract and had good stats and W-L record. I don't think the eagles lose too much without him though. Sanchez, as weird as this is to say, looked good today. The Kelly offense is designed for the QB to look good and perform well. Foles was average this year and his utter lack of speed and arm strength was showing to be an issue. Sanchez looks like he'll perform at about the same level.
I didn't have any Super Bowl expectations for this team, primarily because the defense is terrible, but this doesn't change my outlook. The Eagles can win the division and maybe win a home playoff game. Asking more than that is too much. The team still needs 3 new starters in the secondary to be viable. I am happy for one of them to be Boykins, but they still need a safety and CB in the worst way. Any playmaker on Defense would be nice, as well. Otherwise, the offense will continue to perform. Once Mathis is back, the run game will continue to be better and they will score points. They'll win games, maybe end up 11-5, and potentially make it to the conference championship, if they get the 1st round bye. That's not a bad season, and losing Foles doesn't change that outlook significantly.
I'll stop my eagles rant there.