I'm not sure how it's going to blow safari away. Safari is roughly equivalent to the current state of the art in desktop browsers (the only glaring omission I can think of is indexedDB). If BB10 goes beyond that, it's going to be unusable anyways because it's all going to be BB specific.
Safari could be doing more in allowing webapps to function like native ones- it has the full screen, add to home functionality, but it's not well understood or known. There's no way to register protocols to launch a full screen web app, and a series of hacks are required to stop the entire app doing the elastic "bounce" when you scroll the wrong way.
Safari is good, but it could be a lot better. But I'd expect Google to be leading this charge, not Apple. But Android has basically zero integration options for webapps.
