Wow, there are some quite elaborate ones on there. I thought Apple tried to keep everything simple interface wise. I mean, the one button mouse is still standard and you have to activate the right click. I actually like this approach. I mean I can use the trackpads whole surface, resting my last thumb joint on the button. Right-clicking works by tapping two fingers. Scrolling is with 2 fingers too. For web surfing, i prefer using the trackpad because 2D scrolling with a mouse is kinda awkward, even with the mighty mouse.
I for one welcome our new multi-touch overlords. That's one of those hardware features that makes you want to upgrade even your computer does everything you need it to do right now.