Akex Williamson at RedHat, one of the hybrid graphics linux team members, has written a new kernel module called asus-switcheroo:
This module, that has mostly been tested on an Asus UL30VT and works only with the nouveau drivers, can switch from the Intel to the Nvidia card with the nouveau drivers by presenting the Nvidia card to the Intel drivers. It currently uses jprobe to notify the presence or absence of the nvidia card to the intel i915 driver.
Although using the discrete graphics card with this module is still experimental at the time of this writing (20110419), the module should allow for using both cards with the nouveau drivers, provided the adequate ACPI methods are present in the laptop's BIOS.
Please use the mailing list to give your feedback on this module: