He'll be coming back down to earth soon enough. He's not going to average 400 yards per game passing.
Actually, if you exclude the game he played in heavy rain he 's averaging 409 YPG already
. And that's against some pretty good defenses in the Cardinals, Packers, and Bears. The rest of the Panthers schedule is no worse than what he's already faced.
I think he could pass for 5,000 yards this season - he only needs about 300 yards per game from here on out to hit that. To put that in perspective, I think Marino holds the single season passing yards record at 5,084. I certainly don't think he's still "sneaking up" on teams at this point. Barring injuries or large amounts of rain, he sure looks on par for a record year.