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The web browser standards is not as bad as it might seem. In reality you only have two browsers, Mozilla and Konqueror. Galeon, Epiphany, Firebird are all based off of the gecko rendering engine so your not getting to much duplication of effort. These derivates are basically just putting on their own front-ends. The KDE guys are doing their own thing along with Apple. There are more important standards that need to be addressed than web browsers. Such as better interop between KDE and Gnome, which freedesktop.org and OSDL-desktop are addressing.
As far as your package management comments, Gentoo does do exactly what you were talking about - not with bittorrent though. It's source based and you can customize your builds through what is called a USE variable. USE variable basically just let you do what configure lets you do by specifying what you do and don't want to build into the program.