See the presentation wiki here for most of the pertinent info from the preso.
“In blogging, does art trump truth?” For four years Odin maintained a blog about someone he was not — a woman — and his wild storytelling quietly garnered up to 70 comments every post, unbeknownst to everyone around him including his wife until he was ‘outed’ by his local newspaper. His commenters wrapped themselves up in the character and gave him/her often unheeded advice, a la yelling at the characters on the TV screen in your living room. Was he deceitful? Did Odin create a fictional work like anyone would read in the New Yorker? Was it OK that his readers didn’t know the lie? When it comes out in book form, which Odin says his blog will (mainly because he can monetize it there and not on the Web, he says), maybe the issue will be clearer.