URL: http://owncloud.org/sync-clients/releases/ ownCloud Client 1.5.1 was released on February 14th. With it comes a major change in the build process: "Imported the ocsync library into miralls repository. Adopted all build systems and packaging to that" (cf. ChangeLog) Thus net-misc/ocsync should be removed after the version bump.
Indeed, I have a working ebuild I made for rc1. Should work fine for final version (just the time needed to run tests) ocsync may stay a few months after that (for #501228), but I'll put blockers in the meantime
owncloud-client-1.5.1 is now in portage, thanks for the report!