Marco Arment:

Apple has set fire to iOS. … If you want to enter a category that’s crowded on iOS 6, and you’re one of the few that exclusively targets iOS 7, your app can look better, work better, and be faster and cheaper to develop than most competing apps.

It’s not the scale of the iPad announcement which represented a whole new category of apps, but Apple has reset the playing field. I think a smart developer would take advantage of this.