Word's new Read Mode lets you scroll through the document by swiping horizontally with your finger. On a desktop with touchscreen monitor, you can change this behavior back to more traditional page navigation if you wish. Click the Touch Mode button on the Quick Access Toolbar -- to the right of the program logo of each application -- and the ribbon toolbar's icons spread out for easier finger access.
Apart from these useful changes, however, touch integration in Office is somewhat erratic. You can use gestures such as tap, pinch, stretch, slide and swipe. But on a 24-inch touchscreen monitor, unfortunately, the text formatting icons were too small for me to use accurately. So, right now, though the suite is usable on a touchscreen device, it's not yet touch-friendly.