That's cool.

One thing though. Wouldn't that run a lot faster if you avoided shelling for every command.

Something like (bearing in mind I know nothing about what syntax *nix shells accept):

for my $dist (sort keys %dists) {
  my $lowered = lc($dist);
  mkdir $lowered;
  chdir $lowered;
  system qq(git init);
  chdir '..';
  for my $release (sort @{ $dists{$dist} } ) {
    open my $SH, "| sh" or die $!;

    print $SH <<EOC;
tar zxvf $dist-$release.tar.gz
rsync -avv $dist-$release/ $lowered
chdir $lowered
mv .cvsignore .gitignore
git diff
git add .
git commit -a -m'$release release
EOC

  }
}
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