Arthas authoress Christie Golden, WorldofWar.net have already got the next one - this time with Richard A. Knaak - set up.
Taking place this Thursday -- that's May 14th -- at 8pm EST, the live chat is mainly focusing on Knaak's latest novel Night of the Dragon, which was released just a few days before Wrath. It continued the adventures of Blue Dragon Kalec and Krasus of the Red Dragonflight. The storyline is particularly relevant to Wrath as it introduces the Twilight Dragonflight (Sarth's minions in Obsidian Sanctum).
Check out the site to sign up and find out the time in your country.