Microsoft has recently released a new version of the "Microsoft Intellimouse Explorer for Bluetooth" with the side-to-side scrollwheel. I picked one up on a whim and unfortunately cannot get it to work with my PB 12" with built-in bluetooth.
I've read through these groups and found several people who have gotten the 1st generation MS Bluetooth mouse to work, but no luck with this one. When you attempt to setup a new bluetooth device (mouse), it recognizes the mouse, but fails when attempting to auto negotiate a key pair. If I select "Other Device" rather than "Mouse" for the device type, you have to enter a new key for pairing, and then there is no way for the mouse to enter that key in return.
Unless I'm missing something obvious (I have found nothing searching the internet), it appears the new mouse will NOT work with the Mac. I'll be returning it to the store, and looking for something else. Bummer ...
Tim