I haven't heard of any touchscreens that distinguish between pointing at something and clicking it, without adding an additional tap gesture or a press of an external button. Allowing both actions in a touchscreen interface combines the expressive power of a mouse (hot zones, tooltips) with the intuition of a touchscreen. It also lets you distinguish between a swipe and a drag -- gestures that are intuitive with this pointing device but difficult or impossible with others.

This feature gives Blackberry a slight edge, like the iPhone's multitouch... Actually, in light of the swipe/drag distinction, I think this feature is more desirable than multitouch. Looking at Apple's recent laptop touchpads, it's obvious that they, too, see the value in such a feature; I wouldn't be surprised to see a similarly clickable screen appear in a future iPhone.