Baltimore hosts the July 11-13, 2008 Shore Leave Sci-Fi Convention at the Marriott's Hunt Valley Inn. While I've never attended myself, they bring in comics and comics-related guests every year.
This year's media guests have all played characters represented in comics: David Hewlett (Stargate: Atlantis & Stargate: SG-1's Dr. Rodney McKay), George Takei (Star Trek's Lt. Hikaru Sulu, Heroes' Kaito Nakamura), Malcolm McDowell (Star Trek: Generations' Dr. Soran, Heroes' Mr. Linderman), Jewel Staite (Firefly's Kaylee Frye, Stargate: Atlantis's Dr. Jennifer Keller), Kate Hewlett (Stargate: Atlantis' Jeanie Miller), Mark Sheppard (Battlestar Galactica's Romo Lampkin, Bionic Woman's Anthony Anthos, Firefly's Badger, 24's Ivan Erwich), and W. Morgan Sheppard (Star Trek VI: The Undiscovered Country's Klingon Commander, Babylon 5's Soul Hunter, Transformers' Captain Witwicky).
Their writer guest list is pretty long and broad, and includes a number of noteworthy names who have created comics work as well as sci-fi stories and novels, including: T.A. Chafin, Greg Cox, Peter David, Keith DeCandido, Michael Jan Friedman, Bob Greenberger, Jeffrey Lang, Polly Luttrull, David Mack (no, not the Kabuki one, the other one), Marco Palmieri, and Howard Weinstein.
Some of the other guests may also be part of the industry and I just don't know -- see the full list for more details!