Vick may have been phenomenal in the preseason, but he played only 15 snaps so far. No one would say a single game is a large enough sample size to predict future success, and 15 snaps is not even a typical full game's workload.
Not to mention that preseason games aren't exactly known for their NFL-caliber intensity.
Vick won the job fair and square and is clearly the superior quarterback when compared to Nick Foles. He has thrown the ball with more accuracy and velocity and looks more mobile, both in the pocket and outside of it. But has he truly fixed all of his fundamental flaws?
Here are four questions Vick will still have to answer during the regular season.
As horrible as the offensive line was in 2012, the fault cannot lie entirely with them for Vick's poor play. Vick also showed an inability to both recognize and respond to blitzing defenders.
The low point of last season was perhaps the game against the New Orleans Saints, where Vick completed only four out of 12 passes against the blitz. He looked like a deer in the headlights, consistently failing to recognize all out blitzes.
Vick may be throwing as well as anyone right now in the preseason, but he has not been blitzed as heavily as in regular season games. And in one instance where he was blitzed, the O-line picked it up and gave him ample time to find DeSean Jackson for a deep touchdown.
Another blitz that game resulted in a rushed throw to Jason Avant which was incomplete, yet another resulted in a quick dump off to Brent Celek on third down, not nearly enough to move the chains.
Already, Vick is not quite as sharp against the blitz as he could be. Can he play well in the regular season when complex zone-blitzing schemes are thrown at him?
The improved O-line should help Vick tremendously, but there will inevitably be situations when the line will be unable to pick up all the blitzers—and Vick will have to use his football IQ to know where the open receiver is.
The question remains as to whether or not Vick will be able to do that consistently.
With better O-line play, Vick's interceptions should go down. But the biggest problem with Vick's play has always been his tendency to fumble the football.
Vick had a whopping 11 fumbles in 2012, 10 in 2011, 11 in 2010, nine in 2006, 11 in 2005, and 16 in 2004. Fumbling is a part of the player he has been for his entire career, and old habits don't die easily.
While Vick has been carrying the football seemingly more securely in the preseason, it remains to be seen if he can secure the ball just as effectively during games of consequence, when defenders will punish you for leaving the pocket.
One play from 2012 immediately comes to mind. At the goal-line, a quarterback draw was called, and Vick had what appeared to be a clear path to the end zone. It looked like a sure touchdown—but before Vick could cross the goal line, Steelers safety Ryan Clark knocked the ball out of Vick's hands, and it was recovered by the Steelers to end the drive.
Vick made a strong effort to protect the ball, holding it with both hands, but ball security is simply not one of his strengths and he fumbled it anyway.
Reports have indicated that Vick has finally learned how to properly hold the football this offseason, but he will have to prove it in the regular season against defenses who will specifically game-plan over how to strip it from him.
One of the most important traits of an NFL starting quarterback is reliability. That doesn't just include consistent play, but it also includes the ability to stay on the field.
Vick, unfortunately, has never been that player.
In only one NFL season has Vick played in all 16 games, namely 2006. Since then, Vick has consistently missed games due to rib injuries and concussions.
With a faster release time—both by Vick and by Kelly's new uptempo offense—it is possible that Vick will be exposed to fewer hits and his injury risk will go down. Kelly also seems intent on running the football more, which will further limit Vick's opportunities for injury.
Still, at 33 years of age, it is difficult to imagine that Vick, given his history, will play an entire 16-game schedule this season. Even if he continues to wear his kevlar vest, his willingness to leave the pocket naturally leaves him susceptible to injury.
All things considered, keeping Nick Foles around may be a good idea.
Vick will always be compared to his predecessor, Donovan McNabb. McNabb may have never won the big game, but he kept the Eagles in consistent playoff contention and won more playoff games than any Eagles QB in franchise history.
In three seasons as the starter, Vick has yet to win the Eagles a single postseason game and has only been to the playoffs once.
In all fairness, Vick cannot be blamed entirely for the Eagles' struggles since McNabb's departure. The Eagles defense declined every year since McNabb's final season in Philly—as did the O-line.
Quarterbacks, however, are measured ultimately by wins and losses. If Vick can ultimately lead the Eagles back to the postseason and win playoff games, then Kelly's decision to retain him will have been a success.
If not, observers will question whether keeping Vick around was worth it.
Follow Yueh Ho on Twitter @YuehHo