Great post over on the official Google blog this morning on the thinking behind their new logo, and the evolution of the logo over the past 17 years:
So why are we doing this now? Once upon a time, Google was one destination that you reached from one device: a desktop PC. These days, people interact with Google products across many different platforms, apps and devices—sometimes all in a single day. You expect Google to help you whenever and wherever you need it, whether it’s on your mobile phone, TV, watch, the dashboard in your car, and yes, even a desktop!