Keith Packard announced the 1.15 RC2 release on Wednesday, but its changes are light and just being about two dozen. Keith acknowledged, "Not a huge number of actual code changes, which either means we aren't getting a lot of testing, or the code is nearly perfect. I'd like to assume the latter, but history indicates it's more likely the former. In which case, I'd like to encourage more testing before we get to the end of the minor bug fix merge in another couple of weeks."
More details on X.Org Server 1.15 RC2 (xorg-server 188.8.131.522) can be found via the mailing list announcement.