Both ThinkSecret and LoopRumors are reporting that the October 26th date for Leopard has been "confirmed" and most likely at a 6 p.m. launch event on that day.
There's been no confirmation that Leopard has yet gone Gold Master, but a Gold Master candidate was released internally last week. We have heard unconfirmed tidbits that the official announcement could come as early as tomorrow (possible Tuesday announcement also noted by Appleinsider)