Beyond net-voip/telepathy-connection-managers, the only remaining ebuilds using this flag in the tree are media-sound/squeezeboxserver + media-sound/squeezecenter (in an invalid way, Bug 307099) and media-libs/libgphoto2 (Bug 307101) (again, just for adding a dep to a metapackage and can't see why it couldn't use zeroconf as well) (Plus, one old version of net-im/pidgin/pidgin, for newer versions already renamed to zeroconf) There's enough duplicated use flags in Gentoo as it is. Thanks.
Fixed
Thanks ;)