It 'works' on non touchscreen PCs. But it is quite cumbersome. Going back and forth all the time between your application, the big start window and all apps is not very convenient. And if you are the unlucky one that ends up with one of those new full screen applications because you double clicked on something, then things get even messier.
The best would be if they installed this new UI when the installer senses a touchscreen (they can do special measures for non rotational disks - SSDs - at installation) and installed the traditional UI for all the other screens.