Great rundown by Graham Spencer at MacStories of places in iOS 10 on the 7 that are enhanced by haptic feedback. Notable ones to me are turning toggle switches on and off, and activating "jiggle mode" to move/delete apps on the Home screen.
Between this and the Taptic Home button, I'm excited to see how Apple's enhancements in this area relate to accessibility. On my 6s Plus, I love the greater emphasis of 3D Touch in iOS 10. Acting on emails or texts from the Lock screen with a force press is fantastic. It's much easier than swiping across. I'm keen to see how the experience differs on the 7 Plus, which has a better Taptic Engine than the one in my 6s Plus.
See also: My MacStories article from March 2015, where I wrote about why haptic feedback matters for accessibility.