Double-Click Must Die revisited
Don't be too quick to dismiss Microsoft's effort to solve the double-click problem. Try it yourself. On any explorer window, select Tools, Options, General:
I believe this feature was introduced with Windows 98; it's an attempt to map everything to the single mouse click, using the web metaphor-- hence the underlining option. Note the subtle selection behavior to accommodate this change; hovering your mouse over an item now selects it.