Eagles really do need to name a starter before the 3rd preseason game. The starters normally dont play the 4th preseason game so next week is the last chance for the starters to get work in a game before the season starts.
I don't mind both Foles and Vick continuing to split reps. Even if Vick is named starter to begin the season (and I think he should be and will be), you know he's going to get injured at some point and Foles will have to play.