UPDATED ON -- 10.20.2010:

From [adult swim] Programming:

Dave Willis (co-creator of ATHF, Squidbillies, and Cheyenne Cinnamon)
Dana Snyder (of Aqua Teen Hunger Force, Squidbillies, and many others)
Jay Wade Edwards (editor for ATHF and Squidbillies)
Andy Sipes (Minoriteam, Code Monkeys, Archer, and Sipes Stories)
Phil Samson (editor for Squidbillies)
Chris "Casper" Kelly (co-creator of Stroker & Hoop)
Michael Kupperman (creator of Snake n' Bacon)
James Urbaniak (voice of Dr. Venture on The Venture Bros.)
Adam de la Pena (creator of Minoriteam and Code Monkeys)
Jon Glaser (creator of Delocated)
Tony Millionaire (creator of The Drinky Crow Show)
Todd Redner (Radical Axis Studios)
Nick Gibbons (Radical Axis Studios)
Christy Karacas (co-creator of Superjail)
Mary Kraft (from ATHF and Squidbillies)
The crew from Floyd County Productions (Sealab, Frisky Dingo, Archer)
Radical Axis Studios (ATHF, Squidbillies, and other shows)
Le SexoFlex
and many more!

Outside of [adult swim]:

Mike Salva - www.projectmeatball.com
Tim Wambolt - www.runningwithscissors.com
Jermaine Fowler - www.jermainefowler.com
Max Gilardi - www.hotdiggedydemon.com
Stephen Leonard - www.giantpancake.com
Dan McCoy - www.9ammeeting.com
Zodiak Paredes - www.theboscoshow.com
Josh McCutchen - www.joshmccutchen.com
Scott McCabe - www.twotrickponyproductions.com
Steven Ryan - www. IndependentTogether.net
Dan Redmond
Four Angry Men
Dave the Puppet Guy
and our own Ashley Lange

Special Apperances by the Nerd Blerp crew, The Gritty Chimp from [adult swim] UK, Joe "Covenant" Lamb, Denise Hudson, and Widgett Walls of NeedCoffee.com

*GUESTS SUBJECT TO CHANGE AT ANY TIME*