To boil it down simply, he's worth the hype.
Colts rookie QB Andrew Luck threw a little more than a dozen passes, and many of them showed an elite-level arm and accuracy. Throwing bullets that hit dimes on 12-yard out routes isn't a fluke or an accident. It's the result of a seriously talented quarterback.
Colts fans have every reason to be excited, and the opponents of the Colts have every reason to be concerned.
Luck was 10-for-15 for 188 yards and two touchdowns, highlighted among that were some legitimately excellent throws. Granted, one of his two touchdowns was on a middle screen in which RB Donald Brown made a nice cut to get outside and untouched for the score, but Luck hit deeper out routes and seam routes worthy of a higher-end starting quarterback in the NFL in his first preseason game.
Expect to see much of the same in his second game.
It's easy to get into the comparisons to former Colts QB Peyton Manning but they really are not at all similar in their delivery or their movement. Luck is clearly the superior athlete, and while he didn't scramble, he moved around the pocket with a sense of purpose, awareness and fluidity. He wasn't rearing back and throwing on every pass, but he had tremendous velocity anyway, showing nearly flawless technique and a powerful arm.
Perhaps best of all, he never seemed off-balance. He kept his feet under him (something Manning mastered many years ago) and was able to deliver the ball on target on nearly every throw.
While he threw decisively to receivers just out of their break, the only possible knock would be his tendency to eye his receiver immediately after the snap. He went to his primary read almost exclusively, but considering it's a preseason game, that's certainly not a real mark against him. If this were a regular season game, It'd be fair to suggest the Steelers play the Colts receivers a bit more aggressively, and expect them to attack the seams quite a bit.
He played well into the second quarter, and the Colts destroyed the Rams in his time. How much the Colts will play Luck tonight remains to be seen, but going against the Steelers 1s (even without OLB James Harrison) will likely prove to be a bit more of a challenge for the rookie than the St. Louis Rams were able to put up.