I just got myself a Magic Mouse since my not-so-old Logitech VX Nano started getting super flaky on me. It’s nice. I’ll probably keep it. But I’ve realized that I’m usually just as effective using the trackpad on my MBP. Plus the gestures work better (or I should say that they are easier to use) on my trackpad.
The point of this post is to say that you need to uninstall USB Overdrive for the new Wireless Mouse Software Update to take its place in the System Preferences. It took me a few reboots to figure that out. Now all is right with the world.