This seems like a project with immediate benefit as well as future benefit. For greatest future benefit my opinion is that the initial Linux packaging system to hit is RPM. As you no doubt know, there are a number of ways of converting Linux packages from form to form, and RPM is well-supported as a source format.
If I may toss in a frivolous "and it would be nice if" comment...
It would be nice if BSDPAN could be hooked into the CPAN testers framework. People who opt in would have the test suite run, and the results sent to reports database.
The lack of this functionality at the present time is one of the main reasons I leave the system Perl alone, and run my own in /usr/local.
This is a worthy goal, but may be harder than you think. Plus, some of the work has already be done for you, look at CPANPLUS which can build debs and other packages for example (CPANPLUS::Dist::*).
You may also want to look at alien which can create debs from RPMs and vice versa.
Lastly, I think that RPM is not as widely used as the .deb package format. Ubuntu is the most widely used linux distro and it is based on debian's .deb package format - as are Xandros, Mepis, et. al.
Sounds very good - if it's a complete solution. I don't really like the "time permitting" part of the proposal :), I think either RPM or .deb must be supported and should be a nonconditional part of the deliverables.
As jeremiah said, we've done a lot of work on this already to make sure CPAN packages can be converted to local package managers. You definitely want to look at CPANPLUS::Dist::* to do the CPAN side of things for you.
In the past, we've had a working ports implementation and I'd be happy to work with you to get it up and running again.