One of the most exciting things to come out of Google I/O was the announcement of what Google is calling "Material Design", better known as the new visual direction for Android, Chrome OS, and their web apps. If you've been following the Google scene in the last 18 months, you'll have noticed that the visual styling is slowly beginning to become cleaner and flatter; it looks as if a broader rollout is about to happen. The single largest complaint I have–at least as far as Android is concerned–is the lack of visual continuity on the platform. Perhaps we'll see a complete overhaul in 4.5 Lollipop. Here's hoping.
Read The Verge's writeup, including a handsomely produced proof-of-concept video, here.