Microsoft has posted a “modern design story” highlighting how the company has made the transition into modern design (including Metro). Microsoft also showcases early design concepts for Windows Phone, highlighting the evolution of the platform.
In the short video (roughly 30 seconds long), we can see how Windows Mobile has transitioned over the years into the current iteration of Windows Phone. As The Verge points out, we can clearly see that the early design was inspired by Windows Media center and Zune. Eventually, we get to see the transition into Live Tiles, which we are now seeing in other products including Windows and Xbox.
You can take a look at the video below. Anyone remember their first Windows Mobile handset?