The X Server found in XFree86 4.8.0 has PCI-X and PCI Express fixes and a few other minor changes. The various ATI drivers in XFree86 have picked up support for new Radeon GPUs, fixes a memory leak, and contains a few other changes. The Intel i830 driver has one bug fix.
The release notes for XFree86 4.8.0 can be read here. Sources and binaries for XFree86 4.8.0 can be found in this directory.