He improved his passing. The only thing indicating he hasn't is a scrimmage in the off season. All other reports of his off season and now one game are that he has dramatically improved his efficiency.
And it's not just that. He looks more comfortable in the pocket, and made much better decisions. Half of a good qb is a good OL, and this years OL also seems much better than last year.
So, will Hill have 78% passing and a qbr of 177 every game this year? Probably not. But he will be MUCH better than 54%. Greg Wrubell was predicting between 63-65% this year and I think he's right. Add that to Hill's rushing yards and you have a very dynamic and dangerous qb and one that could make a run for a heisman this year and (lightly tinted blue goggles on) be a possible finalist next year.