There isn't really any extremely exciting work to be found in the 1.9 release, but there is a lot of bug-fixes and general improvements. Keith has written a message to the X.Org developers to fill them in on the 1.9 status with there being some outstanding patches that he hasn't yet pulled and the 11 bugs that are officially deemed blocker bugs for the 1.9 release.
Due to travel plans, Keith plans to push back the merge window closing by a few days to the 4th of June. The non-critical bug deadline is set for the first of August and the official release is still scheduled for the 20th of August.
It looks like X.Org Server 1.9 will be yet another release that's lacking XKB2, which has been talked about for years, but at least it's looking like it will be the second consecutive X.Org Server release to make it out on time -- rather than months late like has been a frequent occurrence in the past.
X.Org Server 1.9 will be included as part of X.Org 7.6, which is expected for release in September or October. X.Org Server 1.9 will most certainly be found in Fedora 14 and with the likelihood this release will be out in time and not with any aggressive changes, it should be in Ubuntu 10.10.
The state of the 1.9 release can be read about on the xorg-devel list.