I agree generally with what Mark is trying to accomplish. It's clear he wants two things:
1. Single collaboration from all the distributions on a single version of softawre.
2. Ubuntu hatred removed from the Debian project.
Both should be applauded, but the details tell a different story.
First, operating systems package software, apply their branding, patches, etc, and ship it with the distribution. As a result, users shouldn't be going upstream for bugs, as much as they should be going to the distribution. THEN, the package maintainer should take the concerns upstream. After all, he took a specific package version, and should be able to communicate to the developer clearly.
Imagine if every distribution sourced a single upstream version. First, each operating system will package the software (differently, that is- RPM, TAR.GZ, DEB, etc) with their patches that work with their operating system. They'll apply their branding, and such. At this point, it's not the same as upstream. It's already different. So, where do the end users go for support? If they go upstream, it might just be a packaging issue, perhaps a conflict with another package. If they go to the package maintainer, then we're back to square one, where no one benefits from collaboration.
It's a bit short sighted, if you ask me. The concern really shouldn't be about collaborating packages together, but when building packages from upstream, not creating mini-forks, if you will. Keep it pristine. I should be able to take a DEB for Ubuntu, and install it on Debian. I should be able to take apart the DEB, and build an RPM that installs on Fedora, RHEL or even SUSE. Hell, I should be able to make a TAR.GZ, and install on Arch or Slackware.
No, the issue isn't distributions collaborating interdependantly, a noteworthy goal, but the distributions should be applying as little as possible to the packages to make it as close to a specific upstream version as possible. This is where FreeBSD and Arch shine. It's the upstream source, packaged in a tarball, and compiled|installed on the end user's machine.
I look at Ubuntu, and the contributions they've made to GNU/Linux, and it's impressive. However, they've also diverged so much from upstream, that it's difficult to take the Ubuntu packages and install them on a Debian system, or otherwise. It's becoming wholly Ubuntu-dependent. Other distributions shouldn't be following suit, creating distribution-specific patchwork. Other distributions should be working with upstream closely, making sure their software is kept as pristine as possible. Let upstream determine the version that the distribution maintains.