"Flat" was king in 2013. The days of shadowing and embossing are gone, meaning most brands are turning away from 3D effects.
This is largely due to marketers' embrace of mobile as an integral part of their campaigns, and the need to look as good on a phone screen as on a physical product.
The best corporate logo changes of 2013 managed to bring a new level of relevancy to top brands without sacrificing recognition, essential components to a successful rebranding.