It's identical to Aaron Rodgers' release coming out of Cal. It's not Brady's or Manning's, but it's definitely not bad. The important thing is that he doesn't have any problems getting arc on the ball, and that it's a very quick release.
The only thing about Luck that isn't elite is his deep ball. Sometimes he floats them up a little bit. Other times it's a beautiful rainbow that hits his man in stride. That said I think it's just about a tweak in his release, and his game will be flawless. I've never seen a QB coming out of college that's even close to as good as Luck. Talent wise, and the fact that Luck is already developed like a 5 year NFL vet.
I think other than the Leftwhich/Tebow wind up throw styles,the release is greatly overrated.Its mostly in the wrist,if you're wind-to-arc ratio is about a half a second to a second and a half,you can make up for the fault with a strong flick of the wrist.