There are still about 40 subversion overlays in layman, but there is no listing of them on overlays.gentoo.org. The main page still mentions the hardware outage from January and claims that "The SVN project listing will be restored shortly."
Re-assigning to infra, should be their area
Listing is restored. The list was generated manually, assuming no new SVN repsitories are created. Ping me if you still need an update.