I agree that finger gestures make up for whatever I have lost from multiple buttons. But I still lose a lot of time every day trying to use the right-click on my mouse. Opening new tabs is a pain and opening new instances of an application is a pain when i go to right click the dock (yes i know you can cmd-click or cmd-N, but thats not always an option).

edit: one last point before this thread ends, trackpads are awesome, computer interaction without one has become much more difficult for me. However they are much too modal, it's fine to make them simple for beginning users who misclick a bunch, but throw a bone to the experienced users who want some power in their interface.