I don't think that Apple needs to introduce a two-button mouse. If you want a two, three, four,...button mouse, please pick one up. However, I like the fact that Apple designs it system to function with a single button - its the simplest solution.
Plus, why do you need two buttons when it can be done with one? Namely, you can access contextual menus with Click + HOLD. If you just click on an item and hold it, the contextual menu pops up right under your pointer. Your in a hold pattern already, so just zip up or down the contextual menu to your item, and let go to implement. You don't have to use the Ctrl to get the contextual menu.
People seem used to the right-mouse form their experience with Windows and other systems, but Apple is MORE convenient and, quite frankly more compatible, than them because with Apple you can use:
Right Mouse click
Ctrl + click
Click + HOLD
Windows only supports Right Mouse click for contextual menus, and doesn't support Click + HOLD at all! Plus, even if you right mouse click on a Windows item, you have to click and let go, navigate to your choice, and then click again. How or why is this considered easier than Apple's implementation?!