The story and screen shots are based on reports from users of the Office 15 Technical Preview. No doubt, Microsoft heard from users that they didn't want to be forced into using a touch interface, and the layout of the screens shown by Foley indicates that Touch is a distinct mode of the program, allowing users to move between it and a conventional keyboard/mouse UI. Foley's source says the button doesn't actually do anything yet.
InformationWeek Must Reads Oct. 21, 2014InformationWeek's new Must Reads is a compendium of our best recent coverage of digital strategy. Learn why you should learn to embrace DevOps, how to avoid roadblocks for digital projects, what the five steps to API management are, and more.