A modern trackball uses the same interface as modern mice. For the Apple trackpad I'm not sure, but I don't see any reasons why the OS should treat a trackball differently compared to a regular computer mouse.
If you don't have a Mac, there's less to recommend about the Magic Trackpad - most of the advanced gestures won't work, and even the normal things like scrolling are a bit "off". I assume this is because even though the the Magic Trackpad will work like a normal (Windows) mouse, its advantages are in the additional Mac-specific extensions that Apple can build into OSX that makes it shine.
This is my experience when I run Windows 7 on a Macbook and it's trackpad. The Windows trackpads I've used on laptops (Dell, Lenovo) are simply horrible to use and are nowhere close to the Mac + trackpad combo, even with their proprietary drivers installed.