Binary CPAN mirror
Very related to this one, something I would really like to see is a module to generate native packages for as many platforms as possible.
Now there are packers for RedHat and Debian and I believe that CPANPLUS has its own, but they do not share any code and are very specific to their platform. So, making a new packer for, say, Solaris, is a huge task.
The idea would be to create a new module (Module::Packer?) as platform neutral as possible to drive the packing process and handle common tasks (compiling the module, detecting which files have to be installed, etc.) and a set of platform dependant plugins (Module::Packer::RedHat, etc.) that should perform operations like finding dependencies or building the package in the native format.
BTW, this discussion should be moved to the Perl Wiki!