I don't know anything about any other debate.
But here is more info about this one:
Schwarzenegger to take voter questions in televised forum
http://www.sfgate.com/cgi-bin/article.cgi?f=/n/a/2005/10/20/state/n174836D98.DTL
Because the forum will be broadcast only in the heavily Democratic Bay area, its ability to sway voters Schwarzenegger's way is unclear.
Todd Harris, a spokesman for Schwarzenegger's California Recovery Team, said campaign officials are negotiating with stations in other parts of the state to air similar programs, but none had come together yet.
"Whether it will happen before the election, I can't say," Harris said.
We'll need to run a Live thread and be on our good behavior. ;-)