I personally wish they'd use it more too, but the problem generally is most game devs dont want to bother programming something in that will only benefit a portion of the users. when they implement something like anti aliasing tricks, they would prefer it to be readily available to all users. That of course they are also getting monetary benefits from nvidia for their time, as games tend to have a deadline, especially if the dev is under a larger company(EA, Activision, Ubisoft, Square Enix as very generic examples). I personally think it'd be nice to have more hjigh profile physx games, but almost being limited to one hardware, devs don't have as much as a drive to do so then say, add more content that everyone can benefit from. Time is more or less the commodity that prevents this.