New input methods will be the dominant trend of 2012. Tablet computers such as the iPad might seem like a nice alternative to desktop and laptop computers, but I believe they're more than that: They're replacements. Just as the command line (remember that?) gave way to graphical user interfaces, so the mouse will be superseded by touchscreens.
The signs are obvious: Windows 8 and Mac OS X Lion, the latest desktop operating systems, borrow heavy from their mobile counterparts. These new interfaces essentially impose a touchscreen-inspired interface over the traditional desktop environment.
Over time, this half-step will become a whole one, and mobile operating systems will dominate. The transition won't be complete by the end of 2012, but we'll be much further down the path, and using computer mice much less often.