If I'm wrong and a light tap will always work, and a swipe will never be broken up into multiple gestures or ignored altogether, and so on, then I'd be delighted, albeit surprised the technology isn't being used anywhere else.
The N900 does have a stylus, but, personally, I only used it for non-mobile versions of some websites or running X programs that weren't written for touch screens.
Probably the reason the technology is not used elsewhere is that the screen is pretty fragile -- it's plastic, not glass, and soft plastic at that. Scratches do build up, and screen protectors do reduce sensitivity.
Also the N900 is single touch -- the dual touch "magic" didn't exist when the N900 was made.