Keith Packard on Thursday announced the availability of X.Org Server 18.104.22.1685, which should be the last RC before calling 1.15 complete. Keith wrote in his brief release announcement, "We're getting perilously close to 1.15 now; this should be the last RC before we're done next week. If you haven't bothered to test a recent candidate, now would be an awesome time to do so and make sure we're releasing something that's going to work for you."
The release announcement for this newest 1.15 test release and its dozen or so changes can be found via the mailing list. The exciting new features to X.Org Server 1.15 are covered in this article.