AdLarge, Midroll, NPR, Panoply, Podtrac, and WNYC have signed on to present at the first-ever "IAB Podcast Upfront Showcase" which will be held September 10 which will be held at Jerome L. Greene Performance Space at 44 Charlton Street in Manhattan's SoHo district. The one-day event will preview for advertisers and media buyers the latest in innovative podcast programming.