See https://qa.mandriva.com/show_bug.cgi?id=41204#c37 for full details.
Currently hald only assigns the input.touchpad capability to devices that can report pressure information. While this true for synaptics and alps touchpad devices, it is not the case for elantech touchpad devices.
Hald require a wider criteria for assigning this capability, such that devices like the Elantech touchpad are accepted.
By not assigning this capability to touchpad devices, other tools will then not configure X to use an appropriate touchpad driver like the synaptics one.
Following up in this bug. Confirm that it's critical to get Elantech touchpad working on distros such as Mandriva.