I really, really, like the Perl mechanism, and I think we would do well to think if something like that wouldn't suit us, with minor modifications.
The biggest modification which I think is needed to a Perl-like organization is that IMO there is value in knowing what packages are 'blessed' by Guido. In other words, some sort of Q/A mechanism would be good, if it can be kept simple. [Alternatively, let's not put a Q/A mechanism in place and my employer can make money selling that information, the way they do for Perl! =)]
(Remember that lwall copied the Pythonic module mechanism, so Perl and Python modules are quite similar)
That's stretching things a bit (the part after the 'so' doesn't follow from the part before), as there is a lot more to the nature of module systems, but the point is well taken. --david