You can probably find a use for four or five buttons on a trackpad. But they're largely not terribly useful. Apple would have to do something with the buttons that other companies aren't doing for it to be a great solution. Unfortunately I'm not a big fan of Apple's input device design - every mouse they've ever designed (they don't actually make anything) sucked. Big time.

If they added a second button the current trackpad design simply by making a slit down the middle that would probably work out ok. I'd likely assign them both to do the same thing and continue using the two-finger-touch method though. It's still faster than having to reach over to the right side of the button when your finger is on the right side of the pad.

As far as Linux goes, that's an OS for running server applications. I have no desire to ever run it on a desktop/workstation machine.

Bruno