The GNOME 2.28.0 release announcement can be read on the GNOME announce list. The release notes that detail all of the changes in the release of GNOME 2.28 for users, accessibility, and developers can be found on GNOME.org.
GNOME 2.28 has worked its way into most of the distribution updates this fall, including Ubuntu 9.10 and Fedora 12. There are two point releases in the GNOME 2.28 series that are planned, with GNOME 2.28.1 being planned for release on the 21st of October.
Going forward with GNOME 3.0 its first development release is planned for late October while a number of more testing/development releases will follow until the official release of GNOME 3.0 / 2.30 on the 31st of March.