Windows 8's general availability date is October 26 and according to ZD Net's Mary Jo Foley, the launch of the Windows Phone 8 platform will occur on October 29.
October 29 will be the official "launch" of Windows Phone 8, I am told. I'm hearing this event will likely be on the west coast, either in San Francisco or Los Angeles. (Again, I don't know exactly where. A photo studio? Outside an Apple store?) But this is considered the "consumer launch" of the product, with handsets to be made available starting a week or two later, meaning early November, as other sources of mine had indicated.