Conventions are an important aspect of product design. Using accepted conventions can help achieve a better user experience by lowering the barrier to learning a new product.
When Apple’s Unibody MacBooks were released they shattered a number of conventions. Trackpads were based on the desktop mouse experience and thus users were faced with the usual left and right buttons below the trackpad. Unibody MacBooks got rid of all the buttons. Furthermore, Unibody MacBooks added a number of gestures through its MultiTouch interface. Pointing and clicking is moving further and further away from the conventional two button mouse which everyone is familiar with. And with more people buying laptops over desktops, the days of the conventional two button mouse may be over.
Now Apple has challenged the convention by introducing the Magic Mouse — getting rid of the buttons and adding MultiTouch to a desktop mouse. It will be interesting to see if other manufacturers follow suit, as most mobile handset makers followed the iPhone in developing MultiTouch smartphones. If they do not, then the convention will remain and the Magic Mouse will forever be a niche product, like the trackball mouse. The two button mouse has proven itself a champion and has been with us for more than twenty users. It will be difficult to unseat.
Another scenario might be more likely: the complete leapfrogging of MultiTouch devices on the desktop to touch interaction directly with the monitor. This scenario could come to fruition long before Apple’s challenge to the two button mouse is played out.