Beta testing - CPAN tracks intra-module dependencies, and does automated
testing, but only on released modules. It would seem useful to allow
an author to upload a "beta" version of their module, and then run the
tests of a dozen or so modules that depend on it. This way, you would
gain confidence that your next release won't break everyone else's
code (or be able to explain why, if it must.)
Using CPANTS to know what modules depend upon yours and PITA for the
testing subsystem will be a way to test such things.
In fact, what you just asked is already listed in the PITA documentation
as within it's scope.
For lack of a better name, I've called it Fallout Testing.
As opposed to Rot Testing, which is when your module doesn't change, but
makes sure it still works as Perl is upgraded and your dependencies evolve.
Since I've got a terribly bad habit of inventing things that have
existing names, I'm sure someone will correct my on the two above namings.
Adam K