ah. yup, you're right. Ok, i'll actually read the doc :) From man CPAN, there is:

           # list all modules on my disk that have newer versions on C
+PAN
           for $mod (CPAN::Shell->expand("Module","/./")){
             next unless $mod->inst_file;
             next if $mod->uptodate;
             printf "Module %s is installed as %s, could be updated to
+ %s from CPAN\n",          $mod->id, $mod->inst_version, $mod->cpan_v
+ersion;
           }
[download]

Commenting out the "next if $mod->uptodate;" produces code that shows installed modules, version, and cpan version. one-line-ified:

perl -MCPAN -e 'for $m (CPAN::Shell->expand("Module","/./")){printf "%
+s %s (%s)\n",$m->id,$m->inst_version,$m->cpan_version if $m->inst_fil
+e}'
[download]