Keith Packard hoped to close the 1.9 merge window by the end of last week, but a few last minute changes have held it up (particularly with the devPrivate changes). Still pending though are some Quartz changes that will be merged and then also the RandR 1.4 branch. The RandR 1.4 branch isn't as exciting as RandR 1.2, but it's a small update similar to what was RandR 1.3. The RandR 1.4 branch provides per-CRTC pixmap support.
This support, as described in the Resize and Rotate extension documentation, provides "multiple scan-out buffers which applications can create and assign to arbitrary collections of crtcs. These pixmaps can be associated with a window for use with OpenGL or drawn to directly." A RRSetCrtcConfigs request has also been added to the RandR 1.4 specification. Intel has a branch of their xf86-video-intel driver with RandR 1.4 support while the other open-source drivers are likely to follow soon.
Beyond RandR 1.4, there isn't anything too major (in terms of new features) to be found in the X.Org Server 1.9 code-base beyond a lot of miscellaneous work.
Keith is also planning to release X.Org Server 1.9 Release Candidate 1 (RC1) today, but your's truly now has a flight to catch for LinuxTag this week in Berlin. The update regarding the 1.9 merge window closing can be found on xorg-devel.