jason kottke wants safari to be further integrated with other internet applications. judging by his mockups, he just doesn't like the abrupt transition between applications. putting other applications within the browser is just a step away from making the browser a full system user interface. but rather than importing application-handling functionality into a browser, why not pull some of the browser niceties back out into the system's interface? i don't mean actually tying the browser to the operating system, but just using the same interface elements that are popular in browsers within the operating system.
mark pilgrim is toying with the (admitedly evil) idea of intentionally adding a "bug" to safari's handling of CSS for the sake of allowing designers to detect the browser. this functionality can be achieved with minimal harm. a CSS statement such as onlysafari body { display: none; } would be technically valid, and could be interpretted only by safari (despite the lack of any actual <onlysafari> tags in the displayed page). additionally, similar syntax could be handled by all browsers without doing significant damage to the CSS standard.