Microsoft doesn't have any APIs to allow developers to make use of Live Tiles/Modern apps inside Desktop apps. Besides, what is the benefit of Live Tiles? That they notify you of stuff - which programs running in the tray can also do with nicer-looking icons. The tiles also take valuable space reserved for important system folders.
Overall, Microsoft's new take on the Start Menu seems like a total flop.
Yet another attempt to push a space hogging tile UI which isn't optimum for mouse or keyboard. The small tile size is also no match for the Classic Start Menu because it can't display submenus and can't have always-visible text labels.