Indeed, Perl6 has module and class vesioning [1] at the 'language' level. It's pretty interesting on paper, just like everything else about Perl6 (imho).

I wouldn't call populating the global namespace with a modules' contents an inferior default. Some like it that way and I'm glad that Python is flexible enough to allow both implicit and explicit imports.

[1] http://perlcabal.org/syn/S11.html#Versioning