"I think the control scheme is a part of it, the traditional MMO has always had a lot of typing and is dependent on the mouse and keyboard paradigm," Street says. He goes on to mention that conventional wisdom used to dictate that FPS titles couldn't work on consoles either, and Halo summarily proved a lot of folks wrong in that regard.
Along the same lines, Kosak addresses the differences in design from a PC monitor to a television. "On PC you're sitting right in front of a screen, you can have a lot of dense information displayed and very complex control schemes. If you're playing on a couch from a distance with a controller, it requires very different design," he says. Check out more of Blizzard's console questions at CVG.