Beyond Firefox 4.0: Handling an accelerated development cycle

As mentioned above, splitting the packages could work. Also, this problem is not so bad with libraries that don't break compatability. Those that do could follow a -stable / -new naming scheme if needed. I'm running firefox 4 from a repo on F14 that pulled in its own xul-runner, along side the system provided firefox 3 and thunderbird, so it does work (need to check the naming scheme)

Ultimately, I think a more granular update policy makes a lot of sense, and not just in this case. There is no reason that the firefox, xul-runner, or Open Office versions need to be as stable as the kernel version, Xorg version, or DE version throughout the lifetime of a distro.