That Template thing is potentially a tricky bit. Flexability, and the ability to switch on demand, based on the users need(s). I think should be addressed. To my knowledge, there really isn't anything that currently addresses this as effectively, as it could. This option, if done correctly, could possibly set it apart from the others already available.
Then there's the versioning strategy. Based on what? Everyone has their preferred strategy. While some, may choose none -- if only for a "one off".
Just some thought's that come to mind.
--Chris
#!/usr/bin/perl -Tw
use Perl::Always or die;
my $perl_version = (5.12.5);
print $perl_version;