I think that my current packaging ideal would be as follows. The package developer creates a
source meta-package using some reasonably easy-to-understand system which can build to (source
and binary) rpm, deb and similar targets. The developer would of course still need to do a
build on a few different systems (which could however be virtual machines or chroot jails) to
get a set of packages which will install on most distributions. Then the people who would
otherwise have packaged the software for distributions can simply liaise with the developer to
make sure that the meta package complies with any distribution policies. If source is
available, distributions could do automatic rebuilds of the source debs and rpms when they add
the software to their repositories.
I am planning on giving something like this a try when I have time.