From the North American Discworld Convention Update Sept 27th:
The Washington Post's Book World will host a live chat with Terry on Wednesday, Oct 1st at 11 am ET, 8 am PT on their website. You can submit questions or comments now for the chat. Details can be found at http://www.washingtonpost.com/wp-dyn/content/discussion/2008/09/25/DI2008092502168.html . Note that registration may be required for access via the main Book World page at http://www.washingtonpost.com/wp-dyn/content/artsandliving/books/index.html .
Strictly speaking, he's not a comic book writer, although I love his books. However, they have been adapted into comics.