Adam Lasnik of Google announced in a Google Groups thread that they are going to be hosting the third webmaster live chat event this Wednesday, October 22nd and noon (EST) or 9am (PST).
I am personally upset at the time. It is a Jewish holiday and I can not be online to participate, which means I cannot provide a recording and commentary after the session is done. I am sorry about that, but there is no way I can be online at this time.
They are planning on using the Google Moderator tool to facilitate the live chat, plus the audio won't require phone - as they are broadcasting the audio online. JohnMu will be covering a topic named "Scary Webmastering Myths" and there will be tons of Q&A time.
You do not want to miss these events, so make sure to stay tuned to the Google Webmaster Central blog for the official announcement. Personally, I hope they change the time before posting the official announcement (note, Thursday is fine, Friday is fine up until Sundown in EST).
Forum discussion at Google Groups.
Update: It is now official, more details on how to join over here. The date and time are final.