I went and saw him about two weeks ago at the Sydney Opera House, and they've now released the full interview.
Sydney Opera House wrote:
Sir Terry Pratchett is best known for his Discworld series of comic fantasy novels that have been translated into 32 languages and sold 65 million copies. In 2007 he was diagnosed with early onset Alzheimer’s and subsequently began a public discussion about the disease and physician assisted suicide.In his only Sydney talk he took part in a lively discussion about his life and work.
Enjoy!