It was announced at the end of September in 2010 during TechCrunch Disrupt (http://techcrunch.com/2010/09/28/tim-armstrong-we-got-techcr...). Arrington left a year later in September 2011, followed by MG Siegler, Paul Carr, Heather Harde, Sarah Lacy, Robin Wauters, (others?), and now Jason Kincaid.