Arianna Huffington has announced that she will step down as editor-in-chief of the Huffington Post. She says she’ll be moving on to create a health and wellness web service called Thrive Global. Huffington launched HuffPo in 2005 with Jonah Peretti, the late Andrew Breitbart and Ken Lerer. The Huffington Post quickly became a must-read for the rich and powerful, and it changed the way the world of news operated. What is the legacy Huffington will leave behind at HuffPo?