Overview: Q&A wrapped its debut season with a cracking line up to take your questions. Audiences tuned in to see Australia's longest serving Treasurer and soon-to-be civilian, Peter Costello, Minister for Health and Ageing Nicola Roxon, former leader of the Australian Democrats, then a Labor MP and now an academic, Cheryl Kernot, author and journalist, David Marr and former editor of the Op-Ed page of The Australian and a former Liberal adviser, Tom Switzer give us a closing show to remember.