Comment 16 for bug 799754

In the solution proposed by Martin Pitt all the fun happens on multi-DE installations. For example, xubuntu-desktop _depends_ on xubuntu-default-settings, and if a similar package for a different distro gets installed (lubuntu, mythbuntu, elementary, ubuntu-studio, whatever), dpkg complains that two packages contain the same file, presents it like a fatal bug and paralyzes itself.

You can make each package containing such a file provide a virtual package with which it will conflict and which it will replace *cough*, but that makes installing two distro metapackages at the same time impossible, and that sounds pretty ridiculous.

There are also derivatives of derivatives and derivatives of derivatives of derivatives, and with this system they are deeply screwed and are doomed to use ugly workarounds.

Please, use some prioritizing system. Debian's alternatives seem to be the best for this case. It will provide flexibility for generations of derivatives to come. You can also try to utilize GSettings, but it's not as good as a real alternatives system for cases like this.