Currently if you ran #g-cpan.pl Regexp::Common It will create a Regexp-Common ebuild in your overlay. Which is fine and dandy however, we already have Regexp::Common in Portage. But it's called regexp-common. There's a number of ebuilds like this. rac made a patch that fixes this problem and will report back the current lowercase or uppercase package that exists in Portage. I've tested the patch and haven't seen a problem yet. This could easily be pushed in the next rev.
As long as we get the patch... ;)
Click the URL in this bug. That's the patch.
Created attachment 42908 [details, diff] The patch Didn't notice it as patches are usually given as attachments. Helps to keep a paper trail as well.
Applied the patch
No reason to leave this open since it was applied 6+ months ago :)