Advertising Age: Slate is announcing the launch of its own podcasting network, Panoply. The online magazine, the home of 15 podcasts with more than 6.5 million monthly downloads, aims to produce and promote podcasts for other media companies, celebrities and authors. It will also sell ads against those podcasts and share a cut of the revenue. The New York Times, Huffington Post, Real Simple magazine, WBUR in Boston and several others have signed on.