Conversation so far:
What were the regular segments?
There is a frequent (previously biweekly and weekly, but now less frequent) diavlog matchup between the two co-founders.
Who were the cofounders?
Robert Wright and Mickey Kaus.
Around what year did these take place?
CANNOTANSWER.

Question: Did they ever have featured guests?
Self-contained rewrite: Did Robert Wright and Mickey Kaus ever have featured guests on the Bloggingheads.tv regular segments?