The X.Org Plans For Moving Away From HAL
On this Wiki page, Alan explains how this hardware abstraction layer for Linux and other operating systems is currently in use for finding input devices, being notified of input device hot-plugging, mapping system input devices, and setting input device options. X.Org has been using HAL since X Server 1.4 and it continues to be used in the most recent X Server 1.7 series, but the migration away from HAL will likely be completed in time for X Server 1.8. This next version of the X.Org Server is planned for release in March.
In replace of HAL in the X Server will be a lot more of OS-specific code to the operating system's respective libraries for device enumeration and device notification. On Linux this means connecting a lot of libudev directly into the X Server. Instead of the input device options being stored in HAL FDI files, the X Server will begin supporting a xorg.conf.d directory for handling input driver options. These new files will utilize a new syntax for matching the options with the respective devices. While the X Server will be picking up this directory support, editing the xorg.conf will remain supported and a valid option.
This code is not yet in place, but it's the current plans for dropping HAL from the X Server for input devices, since the upstream project itself is stopping development in favor of supporting DeviceKit and other projects.