I kinda think that Apple may allow Mac Minis run on MagSafe ports, and re-design the display's base to exactly fit a Mac Mini in (even include some screws and holes/nuts to allow users permanently connect their Mac Mini to the display). This combinition will definitely profit, and even can obsolote iMacs

Some more complicated redesign may include an optical drive into the display and can be accessed through Thunderbolt - makes the display combined with a Mac Mini totally an iMac.