Holo Everywhere was a blog post that was published on the Android Developers Blog outlining the new design guidelines for the Android OS. The post details the new mentality toward Android application design that Google would like Android developers to use.
Here is a link to the complete blog post entry:
http://android-developers.blogspot.com/2012/01/holo-everywhere.html
In addition, the Android team created a website dedicated to Android Design, and the specific guidelines for which developers should try to adhere.
http://developer.android.com/design/index.html
This website looks at the applications that adhere to these guidelines, and focuses on apps that exemplify the vision of the “Holo Everywhere” mentality.