Since the upgraded to Windows 8 Pro, I never used the touchpad of my Asus K53SJ at all. Until today and I missed the gestures which are present on many Windows 8 laptops.
That's why I started my search for the right drivers. Asus provides some drivers, but they only make the touchpad work for basic use.
If you want to make the Windows 8 touch-pad gestures work on your Elantech equipped notebook you have to install the latest drivers from this page. At this moment they are more recent and extensive than the drivers provided by Asus.
After the installation and the required reboot your mouse properties should show a Elan tab and the installed Elan PS/2 device in your mouse properties window.
Optionally you could also download the latest ATK package for Windows 8. It makes your keyboard (Fn) shortcuts work in Windows 8 style. This means you don't get those fancy pictures from Asus when you control for instance your volume, but the nice Windows 8 styled volume bar.