as you can read it here: http://www-users.kawo2.rwth-aachen.de/~razzfazz/
an user has made some scripts that enable the cool new Apple PB trackpad features on your old laptops as well.
For instructions visit the site above further you can download the scripts here:All(XY and Rotation)XYRotation
Just download the scripts and click on the modified.command script. It will check if your laptop supports the new features and load the new drivers until you do a reboot. You can also permanently install the drivers. Take a look at the website posted above.
On my powerbook 12' 1.33 it works perfectly. I can only recommend it to everyone. Further if you put two fingers on the trackpad and perform a click it will be recognized as a right mouse click. Great!