We want to stabilize Perl 5.24 on Gentoo pretty soon (meaning in a few weeks), and do actually not expect any big surprises there. If you are running a stable installation, are willing to do some testing, and are familiar with our Gentoo bugzilla and with filing bug reports, then you might just be the right volunteer to give it a try in advance!
Here's what to do:
Step 1: Update app-admin/perl-cleaner to current ~arch.
I'm deliberately not supplying any version number here, since I might do another release, but you should at least have perl-cleaner-2.25.
Step 2: Make sure your system is uptodate (emerge -uDNav world) and do a depclean step (emerge --depclean --ask).
Step 3: Download the current stabilization list from bug 604602 and place it into your /etc/portage/package.keywords or /etc/portage/package.accept_keywords.
Step 4: Update your world (emerge -uDNav world), which triggers the perl update and the module rebuild.
Step 5: Run "perl-cleaner --all" (you might also want to try "perl-cleaner --all --delete-leftovers").
... and make sure you file bugs for any problems you encounter, during the update and afterwards! Feedback is also appreciated if all goes fine; then you best leave a comment here on the blog post.