They need to concentrate on making this work in closed environments where the developer/designer is certain that a compatible browser is being used; it will be many years before someone can use this for a practical application on the "open web."

Basically, iPhone-specific websites could make them all of their money, if they could make it work correctly with the browser (the front page looked fine, but the font sample page seemed to be a bit off). In fact, I would use and pay for this myself if it were marketed as an enhanced typography library for iPhone web apps.