I created a new System Preference Module called Internet. It is intended to hold system-wide configurations for Internet applications, a bit like Macintosh had up to version 10.2 (or, for that matter, even the older System 7.5 up to 9... or SGI Irix IndigoMagic...).
Currently, the preference implemented is the default browser selection (used by NSWorkspace when it has to open URLs). The registered browsers are presented, they are set immediately on selection and the corresponding application icon is conveniently displayed.
Currently the selection of browsers is essentially limited to Vespucci and SWK's test-bed SWK Browser. Browser wrappers are not supported because they are unable to register with NSWorkspace correctly as they can't open URLs.