This update also enables three-finger drag gesture and inertial scrolling for older Mac portables listed on this support page for the update. Something our own Chris Rawson pointed out was possible.
Oh, and there's a new Preference pane! From Apple's page:
This update also installs a Trackpad System Preferences pane for configuring Magic Trackpad on Intel-based Mac desktop computers that support Mac OS X v10.6.4 and above.
If you find anything wonky, let us know in the comments (and report the bug to Apple as well).