A new patent app has turned up that Apple filed back in April of 2009. The application is interesting because it outlines a cool method Apple dreamed up of offering haptics feedback with multitouch screens.
The application was titled "Multi Touch with Multi Haptics" and I bet we see the tech turn up on the iPad and the iPhone eventually. The patent shows a method of putting numerous haptic actuators behind the touchscreen.
With multiple actuators, Apple can provide different haptic feedback reactions for different gestures on a multiple touch screen. That would presumably mean you could do a gesture like pinch and feel one type of feedback and then swipe to change pages and get a different haptic sensation.