The release is imminent. Ubuntu is developed in the open, so you get to see candidate release images on the page linked.
Ubuntu is not released until the release is announced. If you're in doubt, expect to see an announcement on the ubuntu-announce mailing list, or its archive at https://lists.ubuntu.com/archives/ubuntu-announce/
Also see #ubuntu-release-party on Freenode. At the moment, the topic says "... No, it's not out yet | No, we don't have a set time for release"
(written as of Thu, 17 Oct 2013 10:55:59 +0000; obviously this post will become incorrect as soon as it actually is released)