One of the planned development changes for Ubuntu 9.04 (the Jaunty Jackalope) is transitioning all Ubuntu source packages to having their own Bazaar repositories. From there, anyone can then clone these source-code repositories and do whatever they wish. For now the Bazaar repositories for most of the Ubuntu source packages are being housed at package-import.ubuntu.com, but with time they will be integrating these services with Launchpad and will be introducing several new features...
It'll make the process of patching a package easier, I think.
atm, if you want to patch, you need to get the source of the package (via launchpad, packages.ubuntu.com, or some apt command that nobody really knows), make the patch, then make a .diff, upload the diff to launchpad.net.
but this way you could use bzr to branch a package, make your changes, and then propose your branch for merging.
makes sense as ubuntu is promoting the use of bzr too.
This should make the lives of the package maintainers much easier. It will also (hopefully) facilitate contributions by people who are not running ubuntu - much easier to create a bazaar branch, modify and diff than hunt for the upstream repo, add the ubuntu patches, modify and diff.