I still like having the scrollbar to show how far from the bottom of the document I am.

I would really like to get some sort of iPhone-like implementation. Maybe one that fades in as you come close to the right edge of the window, and in that case with clickable buttons just for legacies sake.

I think Apple could easily do that. All the mice they sell allow for scrolling, as do all their trackpads. And they particularly like not caring about any legacies.

The scroll balls on the mice in my university's library make the screen scroll up, no matter which direction you move them. It forces me to use the scroll bars, which is so annoying that I'm tempted to carry my lovely pocket mouse with me everywhere.